OpenJDK
Encyclopedia
OpenJDK is a free
and open source
implementation of the Java programming language
. It is the result of an effort Sun Microsystems
began in 2006. The implementation is licensed under the GNU General Public License
(GPL) with a linking exception
, which exempts components of the Java class library
from the GPL licensing terms.
OpenJDK will become the official Java SE 7 reference implementation
.
announced in JavaOne 2006
that Java would become open-source software, and on October 25, 2006, at the Oracle OpenWorld
conference, Jonathan Schwartz
said that the company intended to announce the open-sourcing of the core Java Platform within 30 to 60 days.
Sun released the Java HotSpot
virtual machine and compiler as free software
under the GNU General Public License
on November 13, 2006, with a promise that the rest of the JDK (which includes the Java Runtime Environment) would be placed under the GPL by March 2007, "except for a few components that Sun does not have the right to publish in source form under the GPL". According to free-software advocate Richard Stallman
, this would end the "Java trap", the vendor lock-in
that he argues applied to Java and programs written in Java.
(JDK) based almost completely on free and open source code in the first half of 2007 http://www.sun.com/software/opensource/java/faq.jsp#b4, Sun released the complete source code
of the Java Class Library under the GPL on May 8, 2007, except for some limited parts that some third parties licensed to Sun that rejected the terms of the GPL. Included in the list of encumbered parts were several major components of the Java graphical user interface
(GUI). Sun stated that it planned to replace the remaining proprietary
components with alternative implementations and to make the class library completely free.
announced an agreement with Sun, signing Sun's broad contributor agreement (which covers participation in all Sun-led free and open source software projects by all Red Hat engineers) and Sun's OpenJDK Community Technology Compatibility Kit
(TCK) License Agreement (which gives the company access to the test suite that determines whether a project based on openJDK complies with the Java SE 6 specification).
Also on November 2007, the Porters Group was created on OpenJDK to aid in efforts to port OpenJDK to different processor architectures
and operating system
s.
The BSD porting projects http://www.eyesbeyond.com/freebsddom/java/jdk16.html, led by Kurt Miller and Greg Lewis and the Mac OS X
porting project (based on the BSD one) SoyLatte led by Landon Fuller http://landonf.bikemonkey.org/code/macosx/ have expressed interest in joining OpenJDK via the Porters Group and as of January 2008 are part of the mailing list discussions. Another project pending formalization on the Porters Group is the Haiku
Java Team, led by Bryan Varner.
On December 2007, Sun moved the revision control
of OpenJDK from TeamWare to Mercurial
, as part of the process of releasing it to open source
communities.
OpenJDK has comparatively strict procedures of accepting code contributions: every proposed contribution must be reviewed by two of Sun's engineers and the contributor must have signed the Sun/Oracle Contributor Agreement.(SCA/OCA) Preferably, there should also be a jtreg
test demonstrating that the bug has been fixed. Initially, the external patch submission process was slow and commits to the codebase
were only made by Sun engineers, until September 2008. The process has improved and, , simple patches and backports from OpenJDK7 to OpenJDK6 can take place within hours rather than days..
, by far the biggest participant in the Apache Harmony
project, decided to join Oracle
on the OpenJDK project, effectively shifting its efforts from Harmony to OpenJDK. Bob Sutor, IBM's head of Linux and open source, blogged that "IBM will be shifting its development effort from the Apache Project Harmony to OpenJDK".
On November 12, 2010, just three weeks after deprecating its own Java runtime port, Apple Inc. and Oracle announced the OpenJDK project for Mac OS X. Apple will contribute most of the key components, tools and technology required for a Java SE 7 implementation on Mac OS X, including a 32-bit and 64-bit HotSpot-based Java virtual machine, class libraries, a networking stack and the foundation for a new graphical client.
On January 11, 2011, the Mac OS X Port Project was created on OpenJDK, and Apple made the first public contribution of code to the project. The initial Apple contribution built on OpenJDK BSD
port.
In July 2011, SAP AG
announced that SAP officially joined the OpenJDK project.
Since February 15, 2008, there are two separate OpenJDK projects:
, and HotSpot
(the virtual machine
), are now under a GPL
license.
implementation, which is not part of the Java specification) remained, making it possible to build OpenJDK without any binary plugs. The binary plug requirement was later dropped from OpenJDK7 as part of b53 in April 2009.
This was made possible, over the course of the first year, by the work of Sun Microsystems
and the OpenJDK community. Each encumbrance was either released as free and open source software
or replaced with an alternative:
Sun has made continued promises about releasing their web browser plugin and Web Start
implementation as part of OpenJDK, but have so far failed to deliver. The only currently available free plugin and Web Start implementation is that provided by IcedTea.
s, OpenJDK needed to be buildable using only free software
components. Due to the encumbered components in the class library
and implicit assumptions within the build system that the JDK being used to build OpenJDK was a Sun JDK, this was not possible. In order to achieve this goal, a project called IcedTea was started by Red Hat
in June 2007. It began life as an OpenJDK/GNU Classpath
hybrid that could be used to bootstrap
OpenJDK, replacing the encumbrances with code from GNU Classpath.
On November 5, 2007, Red Hat signed both the Sun Contributor Agreement and the OpenJDK Community TCK
License. One of the first benefits of this agreement is tighter alignment with the IcedTea project, which brings together Fedora, the Linux distribution, and JBoss, the application server, technologies in a Linux environment. IcedTea is providing free software alternatives for the few remaining proprietary sections in the OpenJDK project.
In May 2008, the Fedora
9 and Ubuntu 8.04
distributions included IcedTea 6, based completely on free
and open source
code. Fedora 9 was the first version to ship with IcedTea6, based on the OpenJDK6 sources from Sun rather than OpenJDK7. It was also the first to use OpenJDK for the package name (via the OpenJDK trademark agreement) instead of IcedTea.Ubuntu
also first packaged IcedTea7 before later moving to IcedTea6. Packages for IcedTea6 were also created for Debian
and included in lenny. On July 12, 2008, Debian
accepted OpenJDK-6 in unstable, and it is now in stable. OpenJDK is also available on openSUSE
, Red Hat Enterprise Linux
and RHEL derivatives such as CentOS
.
In June 2008, Red Hat announced that the packaged binaries for OpenJDK on Fedora 9, built using IcedTea 6, had passed the Technology Compatibility Kit
tests and could claim to be a fully compatible Java 6 implementation. In July 2009, an IcedTea 6 binary build for Ubuntu 9.04
passed all of the compatibility tests in the Java SE 6 JCK
.
Since August 2008, OpenJDK 7 is runnable on Mac OS X
and other BSD
distributions.
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
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
implementation of the Java programming language
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...
. It is the result of an effort Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
began in 2006. The implementation is licensed 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....
(GPL) with a linking exception
GPL linking exception
A GPL linking exception modifies the GNU General Public License to create a new, modified license. Such modified licenses enable software projects which provide library code, to be "linked to" the programs that use them, without applying the full terms of the GPL to the using program...
, which exempts components of the Java class library
Java Class Library
The Java Class Library is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on any specific operating system, applications cannot rely on any of the existing libraries...
from the GPL licensing terms.
OpenJDK will become the official Java SE 7 reference implementation
Reference implementation
In the software development process, a reference implementation is the standard from which all other implementations, with their attendant customizations, are measured, and to which all improvements are added...
.
Sun's promise and initial release
SunSun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
announced in JavaOne 2006
JavaOne
JavaOne is an annual conference inaugurated in 1996 by Sun Microsystems to discuss Java technologies, primarily among Java developers. JavaOne is held in San Francisco, California typically running from Monday to Thursday. Technical sessions on a variety of topics are held during the day. In the...
that Java would become open-source software, and on October 25, 2006, at the Oracle OpenWorld
Oracle OpenWorld
Oracle OpenWorld is an annual Oracle event for business decision-makers, IT management, and line-of-business end users. It is held in San Francisco, California; São Paulo, Brazil; and Shanghai, China. The world's largest conference for Oracle customers and technologists, Oracle OpenWorld San...
conference, Jonathan Schwartz
Jonathan I. Schwartz
Jonathan Ian Schwartz is the co-founder and Chief Executive Officer of Picture of Health. He was formerly the President and CEO of Sun Microsystems prior to its acquisition by Oracle, and previously the founder and Chief Executive Officer of Lighthouse Design, Ltd., a software company focused on...
said that the company intended to announce the open-sourcing of the core Java Platform within 30 to 60 days.
Sun released the Java HotSpot
HotSpot
HotSpot is a Java virtual machine for desktops and servers, maintained and distributed by Oracle Corporation. It features techniques such as just-in-time compilation and adaptive optimization designed to improve performance.-History:...
virtual machine and compiler as 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...
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....
on November 13, 2006, with a promise that the rest of the JDK (which includes the Java Runtime Environment) would be placed under the GPL by March 2007, "except for a few components that Sun does not have the right to publish in source form under the GPL". According to free-software advocate Richard Stallman
Richard Stallman
Richard Matthew Stallman , often shortened to rms,"'Richard Stallman' is just my mundane name; you can call me 'rms'"|last= Stallman|first= Richard|date= N.D.|work=Richard Stallman's homepage...
, this would end the "Java trap", the vendor lock-in
Vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs...
that he argues applied to Java and programs written in Java.
Release of the class library
Following their promise to release a Java Development KitJava Development Kit
The Java Development Kit is an Oracle Corporation product aimed at Java developers. Since the introduction of Java, it has been by far the most widely used Java SDK. On 17 November 2006, Sun announced that it would be released under the GNU General Public License , thus making it free software...
(JDK) based almost completely on free and open source code in the first half of 2007 http://www.sun.com/software/opensource/java/faq.jsp#b4, Sun released the complete source code
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
of the Java Class Library under the GPL on May 8, 2007, except for some limited parts that some third parties licensed to Sun that rejected the terms of the GPL. Included in the list of encumbered parts were several major components of the Java graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
(GUI). Sun stated that it planned to replace the remaining proprietary
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
components with alternative implementations and to make the class library completely free.
Community improvements
On November 5, 2007, Red HatRed Hat
Red Hat, Inc. is an S&P 500 company in the free and open source software sector, and a major Linux distribution vendor. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide....
announced an agreement with Sun, signing Sun's broad contributor agreement (which covers participation in all Sun-led free and open source software projects by all Red Hat engineers) and Sun's OpenJDK Community Technology Compatibility Kit
Technology Compatibility Kit
A Technology Compatibility Kit is a suite of tests that at least nominally checks a particular alleged implementation of a Java Specification Request for compliance...
(TCK) License Agreement (which gives the company access to the test suite that determines whether a project based on openJDK complies with the Java SE 6 specification).
Also on November 2007, the Porters Group was created on OpenJDK to aid in efforts to port OpenJDK to different processor architectures
Microarchitecture
In computer engineering, microarchitecture , also called computer organization, is the way a given instruction set architecture is implemented on a processor. A given ISA may be implemented with different microarchitectures. Implementations might vary due to different goals of a given design or...
and 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.
The BSD porting projects http://www.eyesbeyond.com/freebsddom/java/jdk16.html, led by Kurt Miller and Greg Lewis and the 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...
porting project (based on the BSD one) SoyLatte led by Landon Fuller http://landonf.bikemonkey.org/code/macosx/ have expressed interest in joining OpenJDK via the Porters Group and as of January 2008 are part of the mailing list discussions. Another project pending formalization on the Porters Group is the Haiku
Haiku (operating system)
Haiku is a free and open source operating system compatible with BeOS. Its development began in 2001, and the operating system became self-hosting in 2008, with the first alpha release in September 2009, the second in May 2010 and the third in June 2011....
Java Team, led by Bryan Varner.
On December 2007, Sun moved the revision control
Revision control
Revision control, also known as version control and source control , is the management of changes to documents, programs, and other information stored as computer files. It is most commonly used in software development, where a team of people may change the same files...
of OpenJDK from TeamWare to Mercurial
Mercurial (software)
Mercurial is a cross-platform, distributed revision control tool for software developers. It is mainly implemented using the Python programming language, but includes a binary diff implementation written in C. It is supported on Windows and Unix-like systems, such as FreeBSD, Mac OS X and Linux...
, as part of the process of releasing it to open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
communities.
OpenJDK has comparatively strict procedures of accepting code contributions: every proposed contribution must be reviewed by two of Sun's engineers and the contributor must have signed the Sun/Oracle Contributor Agreement.(SCA/OCA) Preferably, there should also be a jtreg
JavaTest harness
The JavaTest harness is a regression tests framework specifically designed by Sun Microsystems to tests the reference Java platform implementation....
test demonstrating that the bug has been fixed. Initially, the external patch submission process was slow and commits to the codebase
Codebase
The term codebase, or code base, is used in software development to mean the whole collection of source code used to build a particular application or component. Typically, the codebase includes only human-written source code files, and not, e.g., source code files generated by other tools or...
were only made by Sun engineers, until September 2008. The process has improved and, , simple patches and backports from OpenJDK7 to OpenJDK6 can take place within hours rather than days..
Collaboration with IBM, Apple, and SAP
On October 11, 2010, IBMIBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, by far the biggest participant in the Apache Harmony
Apache Harmony
Apache Harmony was an open source, free Java implementation, developed by the Apache Software Foundation. It was announced in early May 2005 and on October 25, 2006, the Board of Directors voted to make Apache Harmony a top-level project...
project, decided to join Oracle
Oracle Corporation
Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing hardware systems and enterprise software products – particularly database management systems...
on the OpenJDK project, effectively shifting its efforts from Harmony to OpenJDK. Bob Sutor, IBM's head of Linux and open source, blogged that "IBM will be shifting its development effort from the Apache Project Harmony to OpenJDK".
On November 12, 2010, just three weeks after deprecating its own Java runtime port, Apple Inc. and Oracle announced the OpenJDK project for Mac OS X. Apple will contribute most of the key components, tools and technology required for a Java SE 7 implementation on Mac OS X, including a 32-bit and 64-bit HotSpot-based Java virtual machine, class libraries, a networking stack and the foundation for a new graphical client.
On January 11, 2011, the Mac OS X Port Project was created on OpenJDK, and Apple made the first public contribution of code to the project. The initial Apple contribution built on OpenJDK BSD
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
port.
In July 2011, SAP AG
SAP AG
SAP AG is a German software corporation that makes enterprise software to manage business operations and customer relations. Headquartered in Walldorf, Baden-Württemberg, with regional offices around the world, SAP is the market leader in enterprise application software...
announced that SAP officially joined the OpenJDK project.
Supported JDK versions
OpenJDK was initially based only on the JDK 7.0 version of the Java platform.Since February 15, 2008, there are two separate OpenJDK projects:
- The main OpenJDK project, which is based on the JDK 7.0 version of the Java platform,
- The OpenJDK 6 project, which provides an Open-source version of Java 6.0.
Compiler and virtual machine
Sun's Java compiler, javacJavac
javac is the primary Java compiler, included in the Java Development Kit from Oracle Corporation.The compiler accepts source code conforming to the Java language specification and produces bytecode conforming to the Java Virtual Machine Specification .javac is itself written in Java...
, and HotSpot
HotSpot
HotSpot is a Java virtual machine for desktops and servers, maintained and distributed by Oracle Corporation. It features techniques such as just-in-time compilation and adaptive optimization designed to improve performance.-History:...
(the 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...
), are now under a GPL
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....
license.
Class library
As of the first May 2007 release, 4% of the OpenJDK class library remained proprietary. By the appearance of OpenJDK 6 in May 2008, less than 1% (the SNMPSimple Network Management Protocol
Simple Network Management Protocol is an "Internet-standard protocol for managing devices on IP networks. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, and more." It is used mostly in network management systems to monitor...
implementation, which is not part of the Java specification) remained, making it possible to build OpenJDK without any binary plugs. The binary plug requirement was later dropped from OpenJDK7 as part of b53 in April 2009.
This was made possible, over the course of the first year, by the work of Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
and the OpenJDK community. Each encumbrance was either released as free and open source software
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...
or replaced with an alternative:
- All the audio engine code, including the software synthesizerMusical Instrument Digital InterfaceMIDI is an industry-standard protocol, first defined in 1982 by Gordon Hall, that enables electronic musical instruments , computers and other electronic equipment to communicate and synchronize with each other...
, has been released as open source. The proprietaryProprietary softwareProprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
software synthesizer has been replaced by a new synthesizer developed specifically for OpenJDK called Gervill, - All cryptographyCryptographyCryptography is the practice and study of techniques for secure communication in the presence of third parties...
classes used in the class library have been released as open source, - The code that scales and rasterizesRasterisationRasterisation is the task of taking an image described in a vector graphics format and converting it into a raster image for output on a video display or printer, or for storage in a bitmap file format....
fontsComputer fontA computer font is an electronic data file containing a set of glyphs, characters, or symbols such as dingbats. Although the term font first referred to a set of metal type sorts in one style and size, since the 1990s it is generally used to refer to a scalable set of digital shapes that may be...
has been replaced by FreeTypeFreeTypeFreeType is a software library written in C that implements a font rasterization engine. It is used to render text on to bitmaps and provides support for other font-related operations.-Details:... - The native color managementColor managementIn digital imaging systems, color management is the controlled conversion between the color representations of various devices, such as image scanners, digital cameras, monitors, TV screens, film printers, computer printers, offset presses, and corresponding media.The primary goal of color...
system has been replaced by LittleCMSLittleCMSLittleCMS or LCMS is an open source color management system, released as a software library for use in other programs which will allow the use of International Color Consortium profiles. It is licenced under the MIT License Agreement....
. There is a pluggable layer in the JDK, so that the proprietary version can use the old color management system and OpenJDK can use LittleCMS. - The anti-aliasingAnti-aliasingIn digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution...
graphics rasterizerRasterisationRasterisation is the task of taking an image described in a vector graphics format and converting it into a raster image for output on a video display or printer, or for storage in a bitmap file format....
code has been replaced by the open sourceOpen sourceThe term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
Pisces renderer used in the phoneMEPhonemeIn a language or dialect, a phoneme is the smallest segmental unit of sound employed to form meaningful contrasts between utterances....
project. This code is fully functional, but still needs some performance enhancements
Sun has made continued promises about releasing their web browser plugin and Web Start
Java Web Start
In computing, Java Web Start is a framework developed by Sun Microsystems that allows users to start application software for the Java Platform directly from the Internet using a web browser....
implementation as part of OpenJDK, but have so far failed to deliver. The only currently available free plugin and Web Start implementation is that provided by IcedTea.
IcedTea and inclusion in software distributions
To be able to bundle OpenJDK in Fedora and other free Linux distributionLinux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...
s, OpenJDK needed to be buildable using only 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...
components. Due to the encumbered components in the class library
Java Class Library
The Java Class Library is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on any specific operating system, applications cannot rely on any of the existing libraries...
and implicit assumptions within the build system that the JDK being used to build OpenJDK was a Sun JDK, this was not possible. In order to achieve this goal, a project called IcedTea was started by Red Hat
Red Hat
Red Hat, Inc. is an S&P 500 company in the free and open source software sector, and a major Linux distribution vendor. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina with satellite offices worldwide....
in June 2007. It began life as an OpenJDK/GNU Classpath
GNU Classpath
GNU Classpath is a project aiming to create a free software implementation of the standard class library for the Java programming language. Despite the massive size of the library to be created, the majority of the task is already done, including Swing, CORBA, and other major parts. The Classpath...
hybrid that could be used to bootstrap
Bootstrapping (compilers)
In computer science, bootstrapping is the process of writing a compiler in the target programming language which it is intended to compile...
OpenJDK, replacing the encumbrances with code from GNU Classpath.
On November 5, 2007, Red Hat signed both the Sun Contributor Agreement and the OpenJDK Community TCK
Technology Compatibility Kit
A Technology Compatibility Kit is a suite of tests that at least nominally checks a particular alleged implementation of a Java Specification Request for compliance...
License. One of the first benefits of this agreement is tighter alignment with the IcedTea project, which brings together Fedora, the Linux distribution, and JBoss, the application server, technologies in a Linux environment. IcedTea is providing free software alternatives for the few remaining proprietary sections in the OpenJDK project.
In May 2008, the 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...
9 and Ubuntu 8.04
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...
distributions included IcedTea 6, based completely on 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
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
code. Fedora 9 was the first version to ship with IcedTea6, based on the OpenJDK6 sources from Sun rather than OpenJDK7. It was also the first to use OpenJDK for the package name (via the OpenJDK trademark agreement) instead of IcedTea.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...
also first packaged IcedTea7 before later moving to IcedTea6. Packages for IcedTea6 were also created for Debian
Debian
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
and included in lenny. On July 12, 2008, Debian
Debian
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
accepted OpenJDK-6 in unstable, and it is now in stable. OpenJDK is also available on openSUSE
OpenSUSE
openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE...
, Red Hat Enterprise Linux
Red Hat Enterprise Linux
Red Hat Enterprise Linux is a Linux-based operating system developed by Red Hat and targeted toward the commercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64...
and RHEL derivatives such as CentOS
CentOS
CentOS is a free operating system based on Red Hat Enterprise Linux . It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution...
.
In June 2008, Red Hat announced that the packaged binaries for OpenJDK on Fedora 9, built using IcedTea 6, had passed the Technology Compatibility Kit
Technology Compatibility Kit
A Technology Compatibility Kit is a suite of tests that at least nominally checks a particular alleged implementation of a Java Specification Request for compliance...
tests and could claim to be a fully compatible Java 6 implementation. In July 2009, an IcedTea 6 binary build for Ubuntu 9.04
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...
passed all of the compatibility tests in the Java SE 6 JCK
Technology Compatibility Kit
A Technology Compatibility Kit is a suite of tests that at least nominally checks a particular alleged implementation of a Java Specification Request for compliance...
.
Since August 2008, OpenJDK 7 is runnable on 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...
and other BSD
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
distributions.
See also
- javacJavacjavac is the primary Java compiler, included in the Java Development Kit from Oracle Corporation.The compiler accepts source code conforming to the Java language specification and produces bytecode conforming to the Java Virtual Machine Specification .javac is itself written in Java...
, Sun's java compiler, now under a GPL license - HotSpotHotSpotHotSpot is a Java virtual machine for desktops and servers, maintained and distributed by Oracle Corporation. It features techniques such as just-in-time compilation and adaptive optimization designed to improve performance.-History:...
, Sun's Virtual Machine, now under a GPL license - Java Class LibraryJava Class LibraryThe Java Class Library is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on any specific operating system, applications cannot rely on any of the existing libraries...
- Free Java implementationsFree Java implementationsFree Java implementations are software projects that implement Oracle's Java technologies and are distributed under free software licences, thus making them free software...
- Java Platform, Standard EditionJava Platform, Standard EditionJava Platform, Standard Edition or Java SE is a widely used platform for programming in the Java language. It is the Java Platform used to deploy portable applications for general use...
- Apache HarmonyApache HarmonyApache Harmony was an open source, free Java implementation, developed by the Apache Software Foundation. It was announced in early May 2005 and on October 25, 2006, the Board of Directors voted to make Apache Harmony a top-level project...
- IcedTeaIcedTeaIcedTea is a build and integration project for OpenJDK launched by Red Hat in June 2007. The initial goal was to make the Java OpenJDK software which Sun Microsystems released as free software in 2007 usable without requiring any other software that is not free software and hence make it possible...