Mono (software)
Encyclopedia
Mono, pronounced ˈmoʊ.noʊ , is a free and open source project led by Xamarin
(formerly by Novell
and originally by Ximian
) to create an Ecma
standard compliant .NET
-compatible set of tools including, among others, a C# compiler
and a Common Language Runtime
.
The stated purpose of Mono is not only to be able to run Microsoft .NET applications cross-platform, but also to bring better development tools to Linux developers. Mono can be run on Android, BSD, iOS, Linux
, Mac OS X
, Windows
, Solaris, and Unix
operating system
s as well as some game console operating systems such as the ones for the PlayStation 3
, Wii
, and Xbox 360
.
The logo of Mono is a stylized monkey's
face, mono being Spanish
for monkey.
When Microsoft first announced their .NET Framework
in June 2000 it was described as "a new platform based on Internet standards", and in December of that year the underlying Common Language Infrastructure
was published as an open standard, "ECMA-335" - opening up the potential for independent implementations. Miguel de Icaza
of Ximian
believed that .NET had the potential to increase programmer productivity and began investigating whether a Linux version was feasible. Recognizing that their small team could not expect to build and support a full product, they launched the Mono open source project, on July 19, 2001 at the O'Reilly
conference.
After three years development, Mono 1.0 was released on June 30, 2004. Mono evolved from its initial focus of a developer platform for Linux desktop applications to supporting a wide range of architectures and operating systems - including embedded systems.
After Novell
was acquired by Attachmate
in April 2011, Attachmate announced hundreds of layoffs for the Novell workforce, putting in question the future of Mono.
On May 16, Miguel de Icaza announced in his blog that Mono would continue to be supported by Xamarin
, a company he founded after being laid off from Novell. The original Mono team had also moved to the new company. Xamarin plans to keep working on Mono and had planned to rewrite the commercial .NET stacks for iOS and Android from scratch because Novell still owned MonoTouch and Mono for Android at the time. After this announcement, the future of the project was questioned, MonoTouch and Mono for Android being in direct competition with the existing commercial offerings now owned by Attachmate
, and considering that the Xamarin team would have difficulties proving that they did not use technologies they previously developed when they were employed by Novell
for the same work. However, in July 2011, Novell, now a subsidiary of Attachmate, and Xamarin, announced that it granted a perpetual license to Xamarin for Mono, MonoTouch and Mono for Android, which took officially the stewardship of the project.
as well as support for Visual Basic.NET and C# versions 2.0, 3.0, and 4.0. LINQ to Objects, XML, and SQL are part of the distribution. C# 4.0 is now the default mode of operation for the C# compiler. Windows Forms
2.0 is also supported, but not actively developed, and as such its support on Mono is incomplete.
Mono's aim is to achieve full support for the features in .NET 4.0 except WPF
(which the Mono team do not plan to support due to the amount of work it would need), Entity Framework
and WF
, limited WCF
. Some missing parts of the .NET Framework
are under development in an experimental Mono subproject called Olive.
The Mono project has also created a VB.NET compiler as well as a runtime designed for running VB.NET applications. It is currently being developed by Rolf Bjarne Kvinge.
, has been included since Mono 1.9. Moonlight 1.0, which supports the Silverlight 1.0 APIs, was released January 20, 2009. Moonlight 2.0 supports Silverlight 2.0 and some features of Silverlight 3.0. A preview release of Moonlight 3.0 was announced in February 2010 and contains updates to Silverlight 3 support.
The core components include the C# compiler, the virtual machine for the Common Language Infrastructure
and the core class libraries. These components are based on the Ecma-334 and Ecma-335 standards, allowing Mono to provide a standards compliant, free and open source CLI virtual machine
. Microsoft issued a statement that covers both standards under their Community Promise license
.
The Mono/Linux/GNOME development stack provide tools for application development while using the existing GNOME
and Free and Open Source
libraries. These include: Gtk#
for GUI
development, Mozilla libraries for working with the Gecko rendering engine
, Unix integration libraries (Mono.Posix), database connectivity libraries, a security stack, and the XML schema language RelaxNG. Gtk# allows Mono applications to integrate into the Gnome desktop as native applications. The database libraries provide connectivity to the object-relational database db4o
, Firebird
, Microsoft SQL Server
(MSSQL), MySQL
, Open Database Connectivity
(ODBC), Oracle
, PostgreSQL
, SQLite
, and many others. The Mono project tracks developing database components at its website.
The Microsoft compatibility stack provides a pathway for porting Windows .NET applications to GNU/Linux. This group of components include ADO.NET
, ASP.NET
, and Windows.Forms
, among others. As these components are not covered by Ecma
standards, some of them remain subject to patent fears and concerns.
The major components of Mono include:
, MIPS
(in 32-bit mode only), SPARC
, PowerPC
, S390 (in 64-bit mode), x86, x86-64
and IA-64 for 64-bit modes.
The code generator is exposed in three modes:
Starting with Mono 2.6, it is possible to configure Mono to use the Low Level Virtual Machine
(LLVM) as the code generation engine instead of Mono's own code generation engine. This is useful for high performance computing loads and other situations where the execution performance is more important than the startup performance.
Starting with the Mono 2.7 preview, it is no longer necessary to pick one engine over the other at configuration time. The code generation engine can be selected at startup by using the
The current default garbage collector (the "Boehm-Demers-Weiser Conservative Garbage Collector
") has significant limitations compared to commercial garbage-collected runtimes like the Java Virtual Machine
or the .NET framework's runtime, such as a conservative garbage collection can exhibit memory leaks on certain class of applications, this can make it unsuitable for long-running server applications.
, a new generational collector called the "Simple Generational GC" (SGen-GC) is part of Mono. Just like the LLVM code generation engine is now selectable at startup, users can elect to use the new SGen garbage collector by passing the
Currently SGen treats the stack and registers conservatively and pins any objects that could be referenced by any of these roots. The upcoming version of Mono scans the managed stack precisely reducing the number of pinned objects.
Assemblies are the physical packaging of the class libraries. These are .dll files, just like (but not to be confused with) Win32 shared libraries. Examples of assemblies are mscorlib.dll, System.dll, System.Data.dll and Accessibility.dll. Namespaces are often distributed among several assemblies and one assembly can be composed of several files.
The Common Language Specification (CLS) is specified in chapter 6 of ECMA-335 and defines the interface to the CLI, such as conventions like the underlying types for Enum. The Mono compiler generates an image that conforms to the CLS. This is the Common Intermediate Language. The Mono runtime takes this image and runs it. The ECMA standard formally defines a library that conforms to the CLS as a framework.
; that is, it is governed by the CLI's style of memory management and thread safety. Other .NET or Mono applications can use legacy code, which is referred to as unmanaged, by using the System.Runtime.InteropServices libraries to create C# bindings. Many libraries which ship with Mono use this feature of the CLI, such as Gtk#.
In addition, Mono is available on a variety of operating systems and architectures.
Cross-Platform:
MacOS:
Mobile Platforms:
Windows:
has a version of .NET 2.0 now available only for Windows XP
, called the Shared Source CLI (Rotor)
. Microsoft's shared source
license may be insufficient for the needs of the community (it explicitly forbids commercial use).
Free Software Foundation
's abandoned Portable.NET
project.
primarily designed for C# and other .NET languages such as Nemerle, Boo
, and Java
(via IKVM.NET
), although it also supports languages such as C
, C++, Python
, Java
, and Vala
. MonoDevelop was originally a port of SharpDevelop
to Gtk#, but it has since evolved to meet the needs of Mono developers. The IDE includes class management, built-in help, code completion, Stetic (a GUI designer), project support, and an integrated debugger.
The MonoDoc browser provides access to API documentation and code samples. The documentation browser uses wiki-style content management, allowing developers to edit and improve the documentation.
, are implementations of Mono for iPhone
and Android-based smart-phones. Contrary to Mono itself, they are released under a commercial license only.
MonoTouch allows developers to create C# and .NET based applications that run on the iPhone. It is based on the Mono framework and developed in conjunction with Novell. Unlike Mono applications MonoTouch "Apps" are compiled down to machine code targeted specifically at the Apple iPhone
. This is necessary because the iPhone kernel prevents just-in-time compilers
from executing on the device.
The MonoTouch stack is made up of:
MonoDevelop is used as the primary IDE however additional links to Xcode
and the iPhone simulator have been written.
From April to early September 2010, the future of MonoTouch was put in doubt as Apple introduced new terms for iPhone developers that apparently prohibits them from developing in languages other than C, C++ and Objective-C
, and the use of a middle layer between the iPhone OS platform and iPhone applications. This made the future of MonoTouch, as well as other technologies such as UNITY, uncertain. Then, in September 2010, Apple rescinded this restriction, stating that they were relaxing the language restrictions that they had put in place earlier that year.
, is an implementation of Mono for Android-based smart-phones. It was first released on April 6, 2011. Mono for Android was developed to allow developers to more easily write cross-platform applications that will run on all mobile platforms. In an interview with H-Online, Miguel de Icaza stated, "Our vision is to allow developers to reuse their engine and business logic code across all mobile platforms and swapping out the user interface code for a platform-specific API."
In August 2010, a Microsoft spokesman, Tom Hanrahan of Microsoft’s Open Source Technology Centre, stated, in reference to the lawsuit filed by Oracle against Google over Android's use of Java, that "The type of action Oracle is taking against Google over Java is not going to happen. If a .NET port to Android was through Mono it would fall under the Microsoft Community Promise Agreement."
The Mono for Android stack consists of the following components:
d by Xamarin, similar to other products such as Qt
and the Mozilla Application Suite
. Mono's C# compiler and tools are released under the GNU General Public License
(GPLv2 only) (starting with version 2.0 of Mono, the Mono C# compiler source code will also be available under the MIT X11 License), the runtime libraries under the GNU Lesser General Public License
(LGPLv2 only) and the class libraries under the MIT License
. These are all free software
and open-source license
s and hence Mono is free
and open-source software
.
The license of the C# compiler was changed from the GPL to the MIT X11 license to allow the compiler code to be reused in a few instances where the GPL would have prevented it from being used:
for standardization has been the source of patent violation concerns for much of the life of the project. In particular, discussion has taken place about whether Microsoft could destroy the Mono project through patent suits. So far these concerns have proven to be unfounded.
The base technologies submitted to the ECMA, and therefore also the Unix/GNOME-specific parts, are not problematic due to Microsoft's explicitly placing both ECMA 334 and ECMA 335 standards under the Microsoft Community Promise. The concerns primarily relate to technologies developed by Microsoft on top of the .NET Framework, such as ASP.NET
, ADO.NET
and Windows Forms
(see non-standardized namespaces), i.e. parts composing Mono’s Windows compatibility stack. These technologies are today not fully implemented in Mono and not required for developing Mono-applications, they are simply there for developers and users who need full compatibility with the Windows system.
Should patent issues ever arise, the Mono project's stated strategy for dealing with them is as follows:
In addition, Mono is also included in the list of software that the Open Invention Network
has sworn to protect.
On July 6, 2009, Microsoft announced that it was placing their ECMA 334 and ECMA 335 specifications under their Community Promise pledging that they would not assert their patents against anyone implementing, distributing, or using alternative implementations of .NET. However, their position regarding the non-ECMA components like ASP.NET
, ADO.NET
, and Windows Forms
(which are the bone of contention) remains unclarified.
Following criticism from the Free Software Foundation
's Richard Stallman, Canonical Ltd.
, makers of the Ubuntu
Linux distribution, came out with a Mono Position Statement which states that "It is common practice in the software industry to register patents as protection against litigation, rather than as an intent to litigate. Thus mere existence of a patent, without a claim of infringement, is not sufficient reason to warrant exclusion from the Ubuntu Project." The statement then goes on to say that they would therefore continue to ship Mono in Ubuntu until the patents actually become a real threat rather than simply a perceived threat.
Fedora
Project Leader, Paul Frields, has stated "We haven't come to a legal conclusion that is pat enough for us to make the decision to take mono out."
A range of programs have been developed that use the Mono API
and C#. Some programs written for the Linux Desktop include Banshee, Beagle
, Docky
, F-Spot
, Gbrainy
, GNOME Do
, MonoTorrent, Pinta
, and Tomboy
. A number of video games such as The Sims 3
and Second Life
's scripting language, LSL (although not an official .NET language itself), along with many games based on the Unity game engine
also make use of Mono.
Xamarin
Xamarin is a company created in May 2011 by the engineers that created Mono, MonoTouch and Mono for Android which are cross-platform implementations of the Common Language Infrastructure and Common Language Specifications ....
(formerly by Novell
Novell
Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
and originally by Ximian
Ximian
Ximian was a company that provided free software desktop applications for Linux and Unix based on the GNOME platform. Ximian was founded by Miguel de Icaza and Nat Friedman in October, 1999, and was bought by Novell on August 4, 2003...
) to create an Ecma
Ecma International
Ecma International is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's global reach and activities...
standard compliant .NET
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
-compatible set of tools including, among others, a C# compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...
and a Common Language Runtime
Common Language Runtime
The Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions...
.
The stated purpose of Mono is not only to be able to run Microsoft .NET applications cross-platform, but also to bring better development tools to Linux developers. Mono can be run on Android, BSD, iOS, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
, Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, Solaris, and Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s as well as some game console operating systems such as the ones for the PlayStation 3
PlayStation 3
The is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles...
, Wii
Wii
The Wii is a home video game console released by Nintendo on November 19, 2006. As a seventh-generation console, the Wii primarily competes with Microsoft's Xbox 360 and Sony's PlayStation 3. Nintendo states that its console targets a broader demographic than that of the two others...
, and Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...
.
The logo of Mono is a stylized monkey's
Monkey
A monkey is a primate, either an Old World monkey or a New World monkey. There are about 260 known living species of monkey. Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, monkeys...
face, mono being Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
for monkey.
History
| Date | Version | Notes |
|---|---|---|
| 2004-06-30 | 1.0 | C# 1.0 support |
| 2004-09-21 | 1.1 | |
| 2006-11-09 | 1.2 | C# 2.0 C Sharp 2.0 The programming language C# introduces several new features in version 2.0 . These include:- Partial class :... support |
| 2008-10-06 | 2.0 | Mono's APIs are now in par with .NET 2.0. Introduces the C# 3.0 C Sharp 3.0 The programming language C# version 3.0 was released on 19 November 2007 as part of .NET Framework 3.5. It includes new features inspired by functional programming languages such as Haskell and ML, and is driven largely by the introduction of the Language Integrated Query pattern to the Common... and Visual Basic 8 compilers. New Mono-specific APIs: Mono.Cecil, Mono.Cairo and Mono.Posix. Gtk# 2.12 is released. The Gendarme verification tool and Mono Linker are introduced. |
| 2009-01-13 | 2.2 | Mono switches its JIT engine to a new internal representation that gives it a performance boost and introduces SIMD SIMD Single instruction, multiple data , is a class of parallel computers in Flynn's taxonomy. It describes computers with multiple processing elements that perform the same operation on multiple data simultaneously... support in the Mono.Simd Mono.Simd namespace. Mono introduces Full Ahead of Time compilation that allows developers to create full static applications and debuts the C# Compiler as a Service and the C# Interactive Shell (C# REPL) |
| 2009-03-30 | 2.4 | This release mostly polishes all the features that shipped in 2.2 and became the foundation for the Long-Term support of Mono in SUSE Linux. |
| 2009-12-15 | 2.6 | The Mono runtime is now able to use LLVM as a code generation backend and this release introduces Mono co-routines, the Mono Soft Debugger and the CoreCLR security system required for Moonlight and other Web-based plugins. On the class library System.IO.Packaging, WCF client, WCF server, LINQ to SQL debut. The Interactive shell supports auto-completion and the LINQ to SQL supports multiple database backends. The xbuild build system is introduced. |
| 2010-09-22 | 2.8 | Defaults to .NET 4.0 profile, C# 4.0 C Sharp 4.0 C# 4.0 is the latest version of the C# programming language, which was released on April 11, 2010. Microsoft has released the 4.0 runtime and development environment Visual Studio 2010... support, new generational Garbage Collector, includes Parallel Extensions, WCF Routing, CodeContracts, ASP.NET 4.0, drops the 1.0 profile support; the LLVM engine tuned to support 99.9% of all generated code, runtime selectable llvm and gc; incorporates Dynamic Language Runtime Dynamic Language Runtime The Dynamic Language Runtime from Microsoft is an ongoing effort to bring a set of services that run on top of the Common Language Runtime and provides language services for several different dynamic languages... , MEF Managed Extensibility Framework Managed Extensibility Framework is a component of .NET Framework 4.0 for creating lightweight, extensible applications. It allows application developers to discover and use extensions with no configuration required. It also lets extension developers easily encapsulate code and avoid fragile hard... , ASP.NET MVC2 ASP.NET MVC Framework The ASP.NET MVC Framework is a web application framework that implements the model-view-controller pattern. Based on ASP.NET, it allows software developers to build a Web application as a composition of three roles: Model, View and Controller. A model represents the state of a particular aspect of... , OData Client open source code from Microsoft;. Will become release 3.0 |
| 2011-02-15 | 2.10 |
When Microsoft first announced their .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
in June 2000 it was described as "a new platform based on Internet standards", and in December of that year the underlying Common Language Infrastructure
Common Language Infrastructure
The Common Language Infrastructure is an open specification developed by Microsoft and standardized by ISO and ECMA that describes the executable code and runtime environment that form the core of the Microsoft .NET Framework and the free and open source implementations Mono and Portable.NET...
was published as an open standard, "ECMA-335" - opening up the potential for independent implementations. Miguel de Icaza
Miguel de Icaza
Miguel de Icaza is a Mexican free software programmer, best known for starting the GNOME and Mono projects.-Early years:Miguel de Icaza was born in Mexico City and studied at the Universidad Nacional Autonoma de México but never received a degree. He came from a family of scientists in which his...
of Ximian
Ximian
Ximian was a company that provided free software desktop applications for Linux and Unix based on the GNOME platform. Ximian was founded by Miguel de Icaza and Nat Friedman in October, 1999, and was bought by Novell on August 4, 2003...
believed that .NET had the potential to increase programmer productivity and began investigating whether a Linux version was feasible. Recognizing that their small team could not expect to build and support a full product, they launched the Mono open source project, on July 19, 2001 at the O'Reilly
O'Reilly Media
O'Reilly Media is an American media company established by Tim O'Reilly that publishes books and Web sites and produces conferences on computer technology topics...
conference.
After three years development, Mono 1.0 was released on June 30, 2004. Mono evolved from its initial focus of a developer platform for Linux desktop applications to supporting a wide range of architectures and operating systems - including embedded systems.
After Novell
Novell
Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
was acquired by Attachmate
Attachmate
Attachmate Corporation is a software company owned by an investment group led by Francisco Partners, Golden Gate Capital, and Thoma Cressey Bravo. Attachmate focuses on terminal emulation, legacy modernization, managed file transfer, and enterprise fraud management software. Attachmate Corporation...
in April 2011, Attachmate announced hundreds of layoffs for the Novell workforce, putting in question the future of Mono.
On May 16, Miguel de Icaza announced in his blog that Mono would continue to be supported by Xamarin
Xamarin
Xamarin is a company created in May 2011 by the engineers that created Mono, MonoTouch and Mono for Android which are cross-platform implementations of the Common Language Infrastructure and Common Language Specifications ....
, a company he founded after being laid off from Novell. The original Mono team had also moved to the new company. Xamarin plans to keep working on Mono and had planned to rewrite the commercial .NET stacks for iOS and Android from scratch because Novell still owned MonoTouch and Mono for Android at the time. After this announcement, the future of the project was questioned, MonoTouch and Mono for Android being in direct competition with the existing commercial offerings now owned by Attachmate
Attachmate
Attachmate Corporation is a software company owned by an investment group led by Francisco Partners, Golden Gate Capital, and Thoma Cressey Bravo. Attachmate focuses on terminal emulation, legacy modernization, managed file transfer, and enterprise fraud management software. Attachmate Corporation...
, and considering that the Xamarin team would have difficulties proving that they did not use technologies they previously developed when they were employed by Novell
Novell
Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
for the same work. However, in July 2011, Novell, now a subsidiary of Attachmate, and Xamarin, announced that it granted a perpetual license to Xamarin for Mono, MonoTouch and Mono for Android, which took officially the stewardship of the project.
Current status and roadmap
Mono's current version is 2.10 . This version provides the core API of the .NET Framework.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
as well as support for Visual Basic.NET and C# versions 2.0, 3.0, and 4.0. LINQ to Objects, XML, and SQL are part of the distribution. C# 4.0 is now the default mode of operation for the C# compiler. Windows Forms
Windows Forms
Windows Forms is the name given to the graphical application programming interface included as a part of Microsoft .NET Framework, providing access to native Microsoft Windows interface elements by wrapping the extant Windows API in managed code...
2.0 is also supported, but not actively developed, and as such its support on Mono is incomplete.
Mono's aim is to achieve full support for the features in .NET 4.0 except WPF
Windows Presentation Foundation
Developed by Microsoft, the Windows Presentation Foundation is a computer-software graphical subsystem for rendering user interfaces in Windows-based applications. WPF, previously known as "Avalon", was initially released as part of .NET Framework 3.0. Rather than relying on the older GDI...
(which the Mono team do not plan to support due to the amount of work it would need), Entity Framework
ADO.NET Entity Framework
ADO.NET Entity Framework is an object-relational mapping framework for the .NET Framework.-Overview:ADO.NET Entity Framework abstracts the relational schema of the data that is stored in a database and presents its conceptual schema to the application...
and WF
Windows Workflow Foundation
Windows Workflow Foundation is a Microsoft technology that provides an API, an in-process workflow engine, and a rehostable designer to implement long-running processes as workflows within .NET applications...
, limited WCF
Windows Communication Foundation
The Windows Communication Foundation , previously known as "Indigo", is an application programming interface in the .NET Framework for building connected, service-oriented applications.-The architectures:...
. Some missing parts of the .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
are under development in an experimental Mono subproject called Olive.
The Mono project has also created a VB.NET compiler as well as a runtime designed for running VB.NET applications. It is currently being developed by Rolf Bjarne Kvinge.
Moonlight
An open source implementation of Silverlight, called MoonlightMoonlight (runtime)
Moonlight is a free and open source implementation of Microsoft's Silverlight for Linux and other Unix based operating systems, developed by the Mono Project...
, has been included since Mono 1.9. Moonlight 1.0, which supports the Silverlight 1.0 APIs, was released January 20, 2009. Moonlight 2.0 supports Silverlight 2.0 and some features of Silverlight 3.0. A preview release of Moonlight 3.0 was announced in February 2010 and contains updates to Silverlight 3 support.
Mono components
Mono consists of three groups of components:- Core components
- Mono/Linux/GNOME development stack
- Microsoft compatibility stack
The core components include the C# compiler, the virtual machine for the Common Language Infrastructure
Common Language Infrastructure
The Common Language Infrastructure is an open specification developed by Microsoft and standardized by ISO and ECMA that describes the executable code and runtime environment that form the core of the Microsoft .NET Framework and the free and open source implementations Mono and Portable.NET...
and the core class libraries. These components are based on the Ecma-334 and Ecma-335 standards, allowing Mono to provide a standards compliant, free and open source CLI virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
. Microsoft issued a statement that covers both standards under their Community Promise license
Microsoft Open Specification Promise
The Microsoft Open Specification Promise , is a promise by Microsoft, published in September 2006, to not assert legal rights over certain Microsoft patents on implementations of an included list of technologies....
.
The Mono/Linux/GNOME development stack provide tools for application development while using the existing GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...
and Free and Open Source
Free and open source software
Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...
libraries. These include: Gtk#
Gtk Sharp
Gtk# is a set of .NET bindings for the GTK+ GUI toolkit and assorted GNOME libraries. The library facilitates building graphical GNOME applications using Mono or any other compliant CLR...
for GUI
Gui
Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...
development, Mozilla libraries for working with the Gecko rendering engine
Gecko (layout engine)
Gecko is a free and open source layout engine used in many applications developed by Mozilla Foundation and the Mozilla Corporation , as well as in many other open source software projects....
, Unix integration libraries (Mono.Posix), database connectivity libraries, a security stack, and the XML schema language RelaxNG. Gtk# allows Mono applications to integrate into the Gnome desktop as native applications. The database libraries provide connectivity to the object-relational database db4o
Db4o
db4o is an embeddable open source object database for Java and .NET developers. It is developed, commercially licensed and supported by Versant....
, Firebird
Firebird (database server)
Firebird is an open source SQL relational database management system that runs on Linux, Windows, and a variety of Unix. The database forked from Borland's open source edition of InterBase in 2000, but since Firebird 1.5 the code has been largely rewritten ....
, Microsoft SQL Server
Microsoft SQL Server
Microsoft SQL Server is a relational database server, developed by Microsoft: It is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network...
(MSSQL), MySQL
MySQL
MySQL officially, but also commonly "My Sequel") is a relational database management system that runs as a server providing multi-user access to a number of databases. It is named after developer Michael Widenius' daughter, My...
, Open Database Connectivity
Open Database Connectivity
In computing, ODBC is a standard C interface for accessing database management systems . The designers of ODBC aimed to make it independent of database systems and operating systems...
(ODBC), Oracle
Oracle database
The Oracle Database is an object-relational database management system produced and marketed by Oracle Corporation....
, PostgreSQL
PostgreSQL
PostgreSQL, often simply Postgres, is an object-relational database management system available for many platforms including Linux, FreeBSD, Solaris, MS Windows and Mac OS X. It is released under the PostgreSQL License, which is an MIT-style license, and is thus free and open source software...
, SQLite
SQLite
SQLite is an ACID-compliant embedded relational database management system contained in a relatively small C programming library. The source code for SQLite is in the public domain and implements most of the SQL standard...
, and many others. The Mono project tracks developing database components at its website.
The Microsoft compatibility stack provides a pathway for porting Windows .NET applications to GNU/Linux. This group of components include ADO.NET
ADO.NET
ADO.NET is a set of computer software components that programmers can use to access data and data services. It is a part of the base class library that is included with the Microsoft .NET Framework. It is commonly used by programmers to access and modify data stored in relational database systems,...
, ASP.NET
ASP.NET
ASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
, and Windows.Forms
Windows Forms
Windows Forms is the name given to the graphical application programming interface included as a part of Microsoft .NET Framework, providing access to native Microsoft Windows interface elements by wrapping the extant Windows API in managed code...
, among others. As these components are not covered by Ecma
Ecma International
Ecma International is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's global reach and activities...
standards, some of them remain subject to patent fears and concerns.
Framework architecture
- Code Execution Engine
- Class Libraries
- Base Class LibraryBase Class LibraryThe Base Class Library is a standard library available to all languages using the .NET Framework. .NET includes the BCL in order to encapsulate a large number of common functions, such as file reading and writing, graphic rendering, database interaction, and XML document manipulation, which makes...
- .NET Compatibility Class Libraries
- Mono specific class libraries:
- Cross platform class libraries for both Mono and .NET (Gtk#, Mono.Cecil, Mono.CSharp, Text.Templating)
- Unix-specific class libraries (Posix, FUSEFilesystem in UserspaceFilesystem in Userspace is a loadable kernel module for Unix-like computer operating systems that lets non-privileged users create their own file systems without editing kernel code...
, curses) - Platform-specific class libraries (Mac bindings, iPhone bindings, Android bindings, MeeGo bindings)
- Base Class Library
- ECMA Assemblies.NET assemblyIn the .NET framework, an assembly is a compiled code library used for deployment, versioning, and security. There are two types: process assemblies and library assemblies . A process assembly represents a process that will use classes defined in library assemblies...
- ECMA Metadata.NET metadata.NET metadata, in the Microsoft .NET framework, refers to certain data structures embedded within the Common Intermediate Language code that describes the high-level structure of the code. Metadata describes all classes and class members that are defined in the assembly, and the classes and class...
- Mono's Common Language RuntimeCommon Language RuntimeThe Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions...
- Compatible with the ECMA Common Language InfrastructureCommon Language InfrastructureThe Common Language Infrastructure is an open specification developed by Microsoft and standardized by ISO and ECMA that describes the executable code and runtime environment that form the core of the Microsoft .NET Framework and the free and open source implementations Mono and Portable.NET...
/.NET Common Language RuntimeCommon Language RuntimeThe Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions... - Mono-specific enhancements:
- Mono.SIMD support
- Mono co-routines and continuations.
- Compatible with the ECMA Common Language Infrastructure
- Mono-specific enhancements
- Native interop services and COM interopCOM InteropCOM Interop is a technology included in the .NET CLR that enables COM objects to interact with .NET objects, and vice versa.COM Interop aims to provide access to the existing COM components without requiring that the original component be modified. It tries to make the .NET types equivalent to the...
- Security - Transparent Code Framework
Code Execution Engine
The Mono runtime contains a code execution engine that translates ECMA CIL byte codes into native code and supports a number of processors: ARMARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
, MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
(in 32-bit mode only), SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
, PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
, S390 (in 64-bit mode), x86, x86-64
X86-64
x86-64 is an extension of the x86 instruction set. It supports vastly larger virtual and physical address spaces than are possible on x86, thereby allowing programmers to conveniently work with much larger data sets. x86-64 also provides 64-bit general purpose registers and numerous other...
and IA-64 for 64-bit modes.
The code generator is exposed in three modes:
- Just in time (JIT) compilation: The runtime will turn ECMA CIL byte codes into native code as the code runs.
- Ahead-of-Time (AOT) compilation: this code turns the ECMA CIL byte codes (typically found on a .exe or .dll file) and generates native code stored in an operating system, architecture and CPU specific file (for a foo.exe file, it would produce foo.exe.so on Linux). This mode of operation compiles most of the code that is typically done at runtime. There are some exceptions like trampolinesTrampoline (computers)In computer programming, the word trampoline has a number of meanings, and is generally associated with jumps .- Low Level Programming :...
and other administrative code that still require the JIT to function, so AOT images are not fully standalone. - Full Static Compilation: this mode is only supported on a handful of platforms and takes the Ahead-of-Time compilation process one step further and generates all the trampolines, wrappersWrapper functionA wrapper function is a function in a computer program whose main purpose is to call a second function with little or no additional computation. This is also known as method delegation. Wrapper functions can be used for a number of purposes....
and proxiesProxy patternIn computer programming, the proxy pattern is a software design pattern.A proxy, in its most general form, is a class functioning as an interface to something else...
that are required into a static file that can be statically linked into a program and completely eliminates the need for a JIT at runtime. This is used on Apple's iOS, Sony's PlayStation 3PlayStation 3The is the third home video game console produced by Sony Computer Entertainment and the successor to the PlayStation 2 as part of the PlayStation series. The PlayStation 3 competes with Microsoft's Xbox 360 and Nintendo's Wii as part of the seventh generation of video game consoles...
and Microsoft's XBox 360Xbox 360The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...
operating systems.
Starting with Mono 2.6, it is possible to configure Mono to use the Low Level Virtual Machine
Low Level Virtual Machine
The Low Level Virtual Machine is a compiler infrastructure written in C++ that is designed for compile-time, link-time, run-time, and "idle-time" optimization of programs written in arbitrary programming languages...
(LLVM) as the code generation engine instead of Mono's own code generation engine. This is useful for high performance computing loads and other situations where the execution performance is more important than the startup performance.
Starting with the Mono 2.7 preview, it is no longer necessary to pick one engine over the other at configuration time. The code generation engine can be selected at startup by using the
--llvm or --nollvm command line arguments, and it defaults to the fast Mono code generation engine.Garbage collector
As of Mono 2.8, the Mono runtime ships with two garbage collectors, a generational collector and the Boehm conservative collector.The current default garbage collector (the "Boehm-Demers-Weiser Conservative Garbage Collector
Boehm garbage collector
In computer science, the Boehm-Demers-Weiser garbage collector, often simply known as Boehm GC, is a conservative garbage collector for C and C++.Boehm GC is free software distributed under a permissive free software licence similar to the X11 license....
") has significant limitations compared to commercial garbage-collected runtimes like the Java Virtual Machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
or the .NET framework's runtime, such as a conservative garbage collection can exhibit memory leaks on certain class of applications, this can make it unsuitable for long-running server applications.
, a new generational collector called the "Simple Generational GC" (SGen-GC) is part of Mono. Just like the LLVM code generation engine is now selectable at startup, users can elect to use the new SGen garbage collector by passing the
--gc=sgen switch to the Mono runtime at startup. This new garbage collector has many advantages over a traditional conservative scanner. It uses generational garbage collection where new objects are allocated from a nursery, during the garbage collection cycle, all objects that survived are migrated to an older generation memory pool. The idea being that many objects are transient and can quickly be collected and only a handful of objects are long-term objects that live for the entire life of the application. To improve performance this collector assigns memory pools to each thread to let threads allocate new memory blocks without having to coordinate with other threads. Migration of objects from the nursery to the old generation is done by copying the data from the nursery to the old generation pool and updating any live pointers that point to the data to point to the new location. This can be expensive for large objects, so Mono's SGen uses a separate pool of memory for large objects (Large Object Section) and uses a mark-and-sweep algorithm for those objects.Currently SGen treats the stack and registers conservatively and pins any objects that could be referenced by any of these roots. The upcoming version of Mono scans the managed stack precisely reducing the number of pinned objects.
Class library
The class library provides a comprehensive set of facilities for application development. They are primarily written in C#, but due to the Common Language Specification they can be used by any .NET language. The class library is structured into namespaces, and deployed in shared libraries known as assemblies. Speaking of the .NET framework is primarily referring to this class library.Namespaces and assemblies
Namespaces are a mechanism for logically grouping similar classes into a hierarchical structure. This prevents naming conflicts. The structure is implemented using dot-separated words, where the most common top-level namespace is System, such as System.IO and System.Net. There are other top-level namespaces as well, such as Accessibility and Windows. A user can define a namespace by placing elements inside a namespace block.Assemblies are the physical packaging of the class libraries. These are .dll files, just like (but not to be confused with) Win32 shared libraries. Examples of assemblies are mscorlib.dll, System.dll, System.Data.dll and Accessibility.dll. Namespaces are often distributed among several assemblies and one assembly can be composed of several files.
Common Language Infrastructure and Common Language Specification
The Common Language Infrastructure (CLI), or more commonly known as the Common Language Runtime, is implemented by the Mono executable. The runtime is used to execute compiled .NET applications. The common language infrastructure is defined by the ECMA standard. To run an application, you must invoke the runtime with the relevant parameters.The Common Language Specification (CLS) is specified in chapter 6 of ECMA-335 and defines the interface to the CLI, such as conventions like the underlying types for Enum. The Mono compiler generates an image that conforms to the CLS. This is the Common Intermediate Language. The Mono runtime takes this image and runs it. The ECMA standard formally defines a library that conforms to the CLS as a framework.
Managed and unmanaged code
Within a native .NET/Mono application, all code is managedManaged code
Managed code is a term coined by Microsoft to identify computer program code that requires and will only execute under the "management" of a Common Language Runtime virtual machine ....
; that is, it is governed by the CLI's style of memory management and thread safety. Other .NET or Mono applications can use legacy code, which is referred to as unmanaged, by using the System.Runtime.InteropServices libraries to create C# bindings. Many libraries which ship with Mono use this feature of the CLI, such as Gtk#.
Mono-specific innovations
Mono has innovated in some areas with new extensions to the core C# and CLI specifications:- C# Compiler as a Service (Use the C# compiler as a library).
- C# Interactive Shell.
- SIMD support as part of the Mono.SIMD namespace, where method calls to special vector types are directly mapped to the underlying processor CPU SIMD instructions.
- Full Static Compilation of .NET code (used on Mono/iPhone, Mono/PS3).
- Mono coroutines (used to implement micro-threading code and continuations, mostly for game developers).
- 64-bit "large arrays", although present on the ECMA specification, Mono is the only implementation that supports them.
- Assembly injection to live processes.
- Use of LLVM as JIT backend.
In addition, Mono is available on a variety of operating systems and architectures.
Related projects
Several projects extend Mono and allow developers to use it in their development environment. These projects include:Cross-Platform:
- Banshee Media Player a cross-platform music media player built with Mono and Gtk# and also a driver of dozens of C#-based libraries and projects for media handling.
- BeagleBeagle (software)Beagle is a search system for Linux and other such modern Unix-like systems, enabling the user to search documents, chat logs, email and contact lists in a similar way to Spotlight in Mac OS X, and Windows Search or Google Desktop under Linux or Microsoft Windows...
a search system for Unix systems. - Gecko#, bindings for embedding the layout engine used in Mozilla (GeckoGecko (layout engine)Gecko is a free and open source layout engine used in many applications developed by Mozilla Foundation and the Mozilla Corporation , as well as in many other open source software projects....
). - Gtk#Gtk SharpGtk# is a set of .NET bindings for the GTK+ GUI toolkit and assorted GNOME libraries. The library facilitates building graphical GNOME applications using Mono or any other compliant CLR...
, C# wrappers around the underlying GTK+GTK+GTK+ is a cross-platform widget toolkit for creating graphical user interfaces. It is licensed under the terms of the GNU LGPL, allowing both free and proprietary software to use it. It is one of the most popular toolkits for the X Window System, along with Qt.The name GTK+ originates from GTK;...
and GNOMEGNOMEGNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...
libraries, written in CC (programming language)C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and available on Linux, MacOS and Windows. - Mono Migration Analyzer (MoMA), a tool which aids Windows .NET developers in finding areas in their code that might not be cross-platform and therefore not work in Mono on Linux and other Unixes.
- MonoCrossMonoCrossMonoCross is a C# .NET Model-view-controller framework where the Model and Controller are shared across platforms and the View is implemented for every specific platform and/or target architecture. It allows the development of both native and HTML5 web apps that share business logic and data code...
, a cross-platform Model–view–controller design pattern where the Model and Controller are shared across platforms and the Views are unique for each platform for an optimized User Interface. - MonoDevelopMonoDevelopMonoDevelop is an open source integrated development environment for the Linux platform, Mac OS X, and Microsoft Windows, primarily targeted for the development of software that uses both the Mono and Microsoft .NET frameworks...
an open source and cross platform Integrated Development Environment that supports building applications for ASP.NET, Gtk#, Meego, MonoTouch and Silverlight/Moonlight. - MoonlightMoonlight (runtime)Moonlight is a free and open source implementation of Microsoft's Silverlight for Linux and other Unix based operating systems, developed by the Mono Project...
, an implementation of SilverlightMicrosoft SilverlightMicrosoft Silverlight is an application framework for writing and running rich Internet applications, with features and purposes similar to those of Adobe Flash. The run-time environment for Silverlight is available as a plug-in for web browsers running under Microsoft Windows and Mac OS X...
that uses Mono. - OpenTK, a managed binding for OpenGL, OpenCL and OpenAL.
- Qyoto, C# bindings for the Qt framework.
- Resco MobileBusiness, a cross-platform developer solution for mobile clients.
- Resco MobileCRM, a cross-platform developer solution for mobile clients synchronized with Microsoft Dynamics CRMMicrosoft Dynamics CRMMicrosoft Dynamics CRM is a multi-lingual Customer Relationship Management software package developed by Microsoft. Out of the box, the product focuses mainly on Sales, Marketing, and Service sectors, but Microsoft has been marketing Dynamics CRM as an XRM platform and has been encouraging...
. - ServiceStack a high-performance Open source .NET REST web services framework that simplifies the development of XML, JSON and SOAP Web Services.
- Tao, a collection of graphics and gaming bindings (OpenGL, SDL, Glut, Cg).
MacOS:
- Cocoa#Cocoa SharpCocoa# is a bridge framework on Mac OS X to allow applications developed with the Mono runtime to access the Cocoa API. It provides direct access to the Cocoa API using a dot notation familiar to languages working on the Mono runtime such as C#....
wrappers around the native Mac OS X toolkit (CocoaCocoa (API)Cocoa is Apple's native object-oriented application programming interface for the Mac OS X operating system and—along with the Cocoa Touch extension for gesture recognition and animation—for applications for the iOS operating system, used on Apple devices such as the iPhone, the iPod Touch, and...
) (deprecated). - MonobjcMonobjcMonobjc is a bridge API for Mac OS X to allow applications that run on Mono runtime to access various Mac OS X API.It brings to .NET developers the ability to use in a totally transparent manner and with no native code, most of the Mac OS X API and especially Cocoa...
a set of bindings for programming. - MonoMacMonoMACThe autosomal dominant syndrome associated with monocytopenia, B and NK cell lymphopenia and mycobacterial, fungal and viral infections is a rare genetic disorder first described by Vihn and colleagues in 2010 and is associated with myelodysplasia, cytogenetic abnormalities, pulmonary alveolar...
the new bindings for programming, based on the MonoTouch API design.
Mobile Platforms:
- MonoDroid Mono for the Android operating system. With bindings for the Android APIs.
- MonoTouch Mono for the iPhone, iPad and iPod Touches. With bindings to the iOS APIs.
Windows:
- MonoTools for Visual Studio A Visual Studio plugin that allows Windows developers to target Linux, MacOS right from Visual Studio and integrates with SUSE StudioSUSE StudioSUSE Studio is an online Linux image creation tool by Novell. Users can develop their own Linux OS, software appliance or virtual appliance, mainly choosing which applications and packages they want on their "custom" Linux and how it looks...
.
Other Implementations
MicrosoftMicrosoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
has a version of .NET 2.0 now available only for Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
, called the Shared Source CLI (Rotor)
Shared Source Common Language Infrastructure
The Shared Source Common Language Infrastructure , previously codenamed Rotor, is Microsoft's shared source implementation of the CLI, the core of .NET. Although the SSCLI is not suitable for commercial use due to its license, it does make it possible for programmers to examine the implementation...
. Microsoft's shared source
Shared source
Shared source is an umbrella term covering some of Microsoft's legal mechanisms for software source code distribution. Microsoft's Shared Source Initiative, launched in May 2001, includes a spectrum of technologies and licenses...
license may be insufficient for the needs of the community (it explicitly forbids commercial use).
Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
's abandoned Portable.NET
Portable.NET
Part of the DotGNU project, Portable.NET is a free software and open source software initiative aiming to build a portable toolchain and runtime for Common Language Infrastructure applications. The project focuses on compatibility with the ECMA-334 and ECMA-335 standards and support for .NET's...
project.
MonoDevelop
MonoDevelop is a free GNOME integrated development environmentIntegrated development environment
An integrated development environment is a software application that provides comprehensive facilities to computer programmers for software development...
primarily designed for C# and other .NET languages such as Nemerle, Boo
Boo programming language
Boo is an object-oriented, statically typed, general-purpose programming language that seeks to make use of the Common Language Infrastructure's support for Unicode, internationalization, and web applications, while using a Python-inspired syntax and a special focus on language and compiler...
, and Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
(via IKVM.NET
IKVM.NET
IKVM.NET is an implementation of Java for Mono and the Microsoft .NET Framework. IKVM is free software, distributed under a permissive free software licence.IKVM.NET includes the following components:* A Java Virtual Machine implemented in .NET...
), although it also supports languages such as C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
, C++, Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...
, Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
, and Vala
Vala (programming language)
Vala is a programming language created with the goal of bringing modern language features to C, with no added runtime needs and with little overhead, by targeting the GObject object system. It is being developed by Jürg Billeter and Raffaele Sandrini. The syntax borrows heavily from C#...
. MonoDevelop was originally a port of SharpDevelop
SharpDevelop
SharpDevelop is a free and open source integrated development environment for the Microsoft .NET, Mono, Gtk# and Glade# platforms, and supports development in C#, Visual Basic .NET, Boo, F#, IronPython and IronRuby programming languages.It was designed as a free and lightweight alternative to...
to Gtk#, but it has since evolved to meet the needs of Mono developers. The IDE includes class management, built-in help, code completion, Stetic (a GUI designer), project support, and an integrated debugger.
The MonoDoc browser provides access to API documentation and code samples. The documentation browser uses wiki-style content management, allowing developers to edit and improve the documentation.
MonoTouch and Mono for Android
MonoTouch and Mono for Android, both developed by XamarinXamarin
Xamarin is a company created in May 2011 by the engineers that created Mono, MonoTouch and Mono for Android which are cross-platform implementations of the Common Language Infrastructure and Common Language Specifications ....
, are implementations of Mono for iPhone
IPhone
The iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...
and Android-based smart-phones. Contrary to Mono itself, they are released under a commercial license only.
MonoTouch
| Date | Version | Notes |
|---|---|---|
| 2009-09-14 | MonoTouch 1.0 | Initial release |
| 2010-04-05 | MonoTouch 2.0 | iPad IPad The iPad is a line of tablet computers designed, developed and marketed by Apple Inc., primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. The iPad was introduced on January 27, 2010 by Apple's then-CEO Steve Jobs. Its size and... support |
| 2010-04-16 | MonoTouch 3.0 | iPhone 4 IPhone 4 The iPhone 4 is a touchscreen slate smartphone developed by Apple Inc. It is the fourth generation iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling , consumption of media such as books and periodicals, movies, music, and games, and for general web and e-mail... support |
| 2011-04-06 | MonoTouch 4.0 | |
| 2011-10-12 | MonoTouch 5.0 | Latest version |
MonoTouch allows developers to create C# and .NET based applications that run on the iPhone. It is based on the Mono framework and developed in conjunction with Novell. Unlike Mono applications MonoTouch "Apps" are compiled down to machine code targeted specifically at the Apple iPhone
IPhone
The iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...
. This is necessary because the iPhone kernel prevents just-in-time compilers
Just-in-time compilation
In computing, just-in-time compilation , also known as dynamic translation, is a method to improve the runtime performance of computer programs. Historically, computer programs had two modes of runtime operation, either interpreted or static compilation...
from executing on the device.
The MonoTouch stack is made up of:
- Compilers
- C# from the Mono Project
- Third party compilers like RemObject's Oxygene can target MonoTouch as well
- Core .NET libraries
- Development SDK:
- Linker: used to bundle only the code used in the final application.
- mtouch: the Native compiler and tool used to deploy to the target device.
- Interface BuilderInterface BuilderInterface Builder is a software development application for Apple's Mac OS X operating system. It is part of Xcode , the Apple Developer Connection developer's toolset. Interface Builder allows Cocoa and Carbon developers to create interfaces for applications using a graphical user...
integration tools.
- Libraries that bind the native CocoaTouch APIs.
- MonoDevelop IDE
MonoDevelop is used as the primary IDE however additional links to Xcode
Xcode
Xcode is a suite of tools, developed by Apple, for developing software for Mac OS X and iOS. Xcode 4.2, the latest major version, is available on the Mac App Store for free for Mac OS X 10.7 , and on the Apple Developer Connection website for free to registered developers Xcode is a suite of tools,...
and the iPhone simulator have been written.
From April to early September 2010, the future of MonoTouch was put in doubt as Apple introduced new terms for iPhone developers that apparently prohibits them from developing in languages other than C, C++ and Objective-C
Objective-C
Objective-C is a reflective, object-oriented programming language that adds Smalltalk-style messaging to the C programming language.Today, it is used primarily on Apple's Mac OS X and iOS: two environments derived from the OpenStep standard, though not compliant with it...
, and the use of a middle layer between the iPhone OS platform and iPhone applications. This made the future of MonoTouch, as well as other technologies such as UNITY, uncertain. Then, in September 2010, Apple rescinded this restriction, stating that they were relaxing the language restrictions that they had put in place earlier that year.
Mono for Android
Mono for Android, developed by XamarinXamarin
Xamarin is a company created in May 2011 by the engineers that created Mono, MonoTouch and Mono for Android which are cross-platform implementations of the Common Language Infrastructure and Common Language Specifications ....
, is an implementation of Mono for Android-based smart-phones. It was first released on April 6, 2011. Mono for Android was developed to allow developers to more easily write cross-platform applications that will run on all mobile platforms. In an interview with H-Online, Miguel de Icaza stated, "Our vision is to allow developers to reuse their engine and business logic code across all mobile platforms and swapping out the user interface code for a platform-specific API."
In August 2010, a Microsoft spokesman, Tom Hanrahan of Microsoft’s Open Source Technology Centre, stated, in reference to the lawsuit filed by Oracle against Google over Android's use of Java, that "The type of action Oracle is taking against Google over Java is not going to happen. If a .NET port to Android was through Mono it would fall under the Microsoft Community Promise Agreement."
The Mono for Android stack consists of the following components:
- Mono runtime
- Libraries:
- Core .NET class libraries
- Libraries that bind the native Android/Java APIs
- SDK tools to package, deploy and debug
- Visual Studio 2010 integration to remotely debug and deploy.
License
Mono is dual licenseDual license
Multi-licensing is the practice of distributing software under two or more different sets of terms and conditions. This may mean multiple different licenses or sets of licenses. Prefixes may be used to indicate the number of licenses used, e.g...
d by Xamarin, similar to other products such as Qt
Qt (toolkit)
Qt is a cross-platform application framework that is widely used for developing application software with a graphical user interface , and also used for developing non-GUI programs such as command-line tools and consoles for servers...
and the Mozilla Application Suite
Mozilla Application Suite
The Mozilla Application Suite is a cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition by AOL. It is based on the source code of Netscape Communicator...
. Mono's C# compiler and tools are released under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
(GPLv2 only) (starting with version 2.0 of Mono, the Mono C# compiler source code will also be available under the MIT X11 License), the runtime libraries under the GNU Lesser General Public License
GNU Lesser General Public License
The GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License...
(LGPLv2 only) and the class libraries under the MIT License
MIT License
The MIT License is a free software license originating at the Massachusetts Institute of Technology . It is a permissive license, meaning that it permits reuse within proprietary software provided all copies of the licensed software include a copy of the MIT License terms...
. These are all free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
and open-source license
Open-source license
An open-source license is a copyright license for computer software that makes the source code available for everyone to use. This allows end users to review and modify the source code for their own customization and/or troubleshooting needs...
s and hence Mono is free
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
and open-source software
Open-source software
Open-source software is computer software that is available in source code form: the source code and certain other rights normally reserved for copyright holders are provided under a software license that permits users to study, change, improve and at times also to distribute the software.Open...
.
The license of the C# compiler was changed from the GPL to the MIT X11 license to allow the compiler code to be reused in a few instances where the GPL would have prevented it from being used:
- Mono's Compiler as a Service
- The Mono interactive Shell
- The Mono embeddable C# compiler
- Mono's implementation of the C# 4.0 dynamic binder.
- MonoDevelop's built-in parser and AST graph
Mono and Microsoft's patents
Mono’s implementation of those components of the .NET stack not submitted to the ECMAEcma International
Ecma International is an international, private non-profit standards organization for information and communication systems. It acquired its name in 1994, when the European Computer Manufacturers Association changed its name to reflect the organization's global reach and activities...
for standardization has been the source of patent violation concerns for much of the life of the project. In particular, discussion has taken place about whether Microsoft could destroy the Mono project through patent suits. So far these concerns have proven to be unfounded.
The base technologies submitted to the ECMA, and therefore also the Unix/GNOME-specific parts, are not problematic due to Microsoft's explicitly placing both ECMA 334 and ECMA 335 standards under the Microsoft Community Promise. The concerns primarily relate to technologies developed by Microsoft on top of the .NET Framework, such as ASP.NET
ASP.NET
ASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
, ADO.NET
ADO.NET
ADO.NET is a set of computer software components that programmers can use to access data and data services. It is a part of the base class library that is included with the Microsoft .NET Framework. It is commonly used by programmers to access and modify data stored in relational database systems,...
and Windows Forms
Windows Forms
Windows Forms is the name given to the graphical application programming interface included as a part of Microsoft .NET Framework, providing access to native Microsoft Windows interface elements by wrapping the extant Windows API in managed code...
(see non-standardized namespaces), i.e. parts composing Mono’s Windows compatibility stack. These technologies are today not fully implemented in Mono and not required for developing Mono-applications, they are simply there for developers and users who need full compatibility with the Windows system.
Should patent issues ever arise, the Mono project's stated strategy for dealing with them is as follows:
- Work around the patent by using a different implementation technique that retains the API, but changes the mechanism; if that is not possible, they would
- Remove the pieces of code that were covered by those patents, and also
- Find prior art that would render the patent useless.
In addition, Mono is also included in the list of software that the Open Invention Network
Open Invention Network
The Open Invention Network is a company that acquires patents and licenses them royalty free to entities which, in turn, agree not to assert their own patents against Linux and Linux-related systems and applications.-History:...
has sworn to protect.
On July 6, 2009, Microsoft announced that it was placing their ECMA 334 and ECMA 335 specifications under their Community Promise pledging that they would not assert their patents against anyone implementing, distributing, or using alternative implementations of .NET. However, their position regarding the non-ECMA components like ASP.NET
ASP.NET
ASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
, ADO.NET
ADO.NET
ADO.NET is a set of computer software components that programmers can use to access data and data services. It is a part of the base class library that is included with the Microsoft .NET Framework. It is commonly used by programmers to access and modify data stored in relational database systems,...
, and Windows Forms
Windows Forms
Windows Forms is the name given to the graphical application programming interface included as a part of Microsoft .NET Framework, providing access to native Microsoft Windows interface elements by wrapping the extant Windows API in managed code...
(which are the bone of contention) remains unclarified.
Following criticism from the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
's Richard Stallman, Canonical Ltd.
Canonical Ltd.
Canonical Ltd. is a private company founded by South African entrepreneur Mark Shuttleworth to market commercial support and related services for Ubuntu Linux and related projects. Canonical is registered in London and employs staff around the world...
, makers of the Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...
Linux distribution, came out with a Mono Position Statement which states that "It is common practice in the software industry to register patents as protection against litigation, rather than as an intent to litigate. Thus mere existence of a patent, without a claim of infringement, is not sufficient reason to warrant exclusion from the Ubuntu Project." The statement then goes on to say that they would therefore continue to ship Mono in Ubuntu until the patents actually become a real threat rather than simply a perceived threat.
Fedora
Fedora (operating system)
Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...
Project Leader, Paul Frields, has stated "We haven't come to a legal conclusion that is pat enough for us to make the decision to take mono out."
Software developed with Mono
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
and C#. Some programs written for the Linux Desktop include Banshee, Beagle
Beagle (software)
Beagle is a search system for Linux and other such modern Unix-like systems, enabling the user to search documents, chat logs, email and contact lists in a similar way to Spotlight in Mac OS X, and Windows Search or Google Desktop under Linux or Microsoft Windows...
, Docky
Docky
Docky is a dock for the GNOME desktop, very similar in functionality to Mac OS X's Dock. Originally it was an integrated part of Gnome Do, but the two projects separated in late 2009. It is available for distributions such as Debian, Ubuntu, OpenSUSE and Arch Linux.-External links:* *...
, F-Spot
F-Spot
F-Spot is an image organizer, designed to provide personal photo management for the GNOME desktop environment. The name is a play on the words F-Stop and G-Spot.-Features:...
, Gbrainy
Gbrainy
gbrainy is a brain teaser game for GNOME designed for use in education. It is licensed under the GNU GPL. The game was written in C# and has since been ported to the Sugar graphical environment, to Microsoft Windows, and there is also an on-line ....
, GNOME Do
GNOME Do
GNOME Do is a popular, free application launcher for Linux originally created by David Siegel, and currently maintained by Alex Launi...
, MonoTorrent, Pinta
Pinta (software)
Pinta is a lightweight open-source, cross-platform bitmap image drawing and editing program inspired by Paint.NET, a similar image editing program which is limited to Microsoft Windows. Pinta aims to offer a free and open-source simpler alternative to GIMP on the GNOME desktop environment...
, and Tomboy
Tomboy (software)
Tomboy is a free and open-source desktop notetaking application written for Unix-like and Microsoft Windows operating systems, written in C# using Gtk#. Tomboy is part of the GNOME desktop environment, often for personal information management. Its interface is a notepad with a wiki-like linking...
. A number of video games such as The Sims 3
The Sims 3
The Sims 3 is a 2009 strategic life simulation computer game developed by The Sims Studio and published by Electronic Arts. It is the sequel to the best-selling computer game, The Sims 2. It was first released on June 2, 2009 simultaneously for Mac OS X and Microsoft Windows...
and Second Life
Second Life
Second Life is an online virtual world developed by Linden Lab. It was launched on June 23, 2003. A number of free client programs, or Viewers, enable Second Life users, called Residents, to interact with each other through avatars...
's scripting language, LSL (although not an official .NET language itself), along with many games based on the Unity game engine
Unity (game engine)
Unity is an integrated authoring tool for creating 3D video games or other interactive content such as architectural visualizations or real-time 3D animations. Unity's development environment runs on Microsoft Windows and Mac OS X, and the games it produces can be run on Windows, Mac, Xbox 360,...
also make use of Mono.
See also
- Common Language RuntimeCommon Language RuntimeThe Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions...
- Comparison of application virtual machinesComparison of Application Virtual MachinesThis article lists some software virtual machines that are typically used for allowing application bytecode to be portably run on many different computer architectures and operating systems. The application is usually run on the computer using an interpreter or just-in-time compilation...
- DotGNUDotGNUDotGNU is a part of the GNU Project that aims to provide a free software replacement for Microsoft's .NET Framework by Free Software Foundation...
– A free software umbrella project which includes Portable.NET - MonoDevelopMonoDevelopMonoDevelop is an open source integrated development environment for the Linux platform, Mac OS X, and Microsoft Windows, primarily targeted for the development of software that uses both the Mono and Microsoft .NET frameworks...
– An open source IDEIntegrated development environmentAn integrated development environment is a software application that provides comprehensive facilities to computer programmers for software development...
targeting both Mono and Microsoft .NET framework.NET FrameworkThe .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
platforms - Moonlight (runtime)Moonlight (runtime)Moonlight is a free and open source implementation of Microsoft's Silverlight for Linux and other Unix based operating systems, developed by the Mono Project...
, an open-source implementation of MicrosoftMicrosoftMicrosoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
's SilverlightMicrosoft SilverlightMicrosoft Silverlight is an application framework for writing and running rich Internet applications, with features and purposes similar to those of Adobe Flash. The run-time environment for Silverlight is available as a plug-in for web browsers running under Microsoft Windows and Mac OS X...
developed by the Mono Project - Portable.NETPortable.NETPart of the DotGNU project, Portable.NET is a free software and open source software initiative aiming to build a portable toolchain and runtime for Common Language Infrastructure applications. The project focuses on compatibility with the ECMA-334 and ECMA-335 standards and support for .NET's...
– Another free software implementation of ECMA 334 and 335 - Shared Source Common Language InfrastructureShared Source Common Language InfrastructureThe Shared Source Common Language Infrastructure , previously codenamed Rotor, is Microsoft's shared source implementation of the CLI, the core of .NET. Although the SSCLI is not suitable for commercial use due to its license, it does make it possible for programmers to examine the implementation...
– Microsoft's shared source implementation of .NET, previously codenamed Rotor - mod monoMod monomod_mono is a module for the Apache HTTP Server that allows for hosting of ASP.NET pages and other assemblies on multiple platforms by use of the Mono development platform....
– A module for the Apache HTTP ServerApache HTTP ServerThe Apache HTTP Server, commonly referred to as Apache , is web server software notable for playing a key role in the initial growth of the World Wide Web. In 2009 it became the first web server software to surpass the 100 million website milestone...
that allows for hosting of ASP.NETASP.NETASP.NET is a Web application framework developed and marketed by Microsoft to allow programmers to build dynamic Web sites, Web applications and Web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages ...
pages and other assemblies on multiple platforms by use of Mono
External links
- Mono Project Main Page
- MonoTouch Main Page for the port to Apple Inc.'s hand-held products