The C5 Generic Collection Library for C# and CLI is a comprehensive software library of collection classes for the C# programming language and other programming languages on 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...

 (CLI) platform, as implemented by Microsoft

Microsoft

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...

's .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...

 and by the Mono

Mono (software)

Mono, pronounced , is a free and open source project led by Xamarin to create an Ecma standard compliant .NET-compatible set of tools including, among others, a C# compiler and a Common Language Runtime....

 project from 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...

.

The C5 generic collection library is 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...

 and was developed by Niels Kokholm and Peter Sestoft at the IT University of Copenhagen

IT University of Copenhagen

The IT University of Copenhagen is a Danish globally oriented, independent university.The IT University of Copenhagen was established in Copenhagen, Denmark in 1999. At that time, it was - in Danish - called "IT-højskolen"...

 in Denmark

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 with some financial support from Microsoft Research

Microsoft Research

Microsoft Research is the research division of Microsoft created in 1991 for developing various computer science ideas and integrating them into Microsoft products. It currently employs Turing Award winners C.A.R. Hoare, Butler Lampson, and Charles P...

 University Relations.

The C5 generic collection library is available in source and binary form from the library's web page http://www.itu.dk/research/c5/ along with a technical report / book (ITU-TR-2006-76) describing the library, its use, and its implementation.

Mono

Mono (software)

Mono, pronounced , is a free and open source project led by Xamarin to create an Ecma standard compliant .NET-compatible set of tools including, among others, a C# compiler and a Common Language Runtime....

also bundles the C5 library as a third party API.