The official .NET runtime and development toolkit from Microsoft.

An initiative to create an open source implementation of the .NET runtime and related development tools.

A project (part of the DotGNU) to build a suite of free software tools to build and execute .NET applications, including a C# compiler, assembler, disassembler, and runtime engine. The initial target platform is GNU/Linux, with other platforms to follow in the future.

Community portal dedicated to DotGNU and its projects Portable.NET, phpGroupWare and DGEE; news and articles, downloads and forums.

An open development initiative sponsored by Ximian that is working to develop an open source, Unix version of the Microsoft .NET development platform.

A shared source implementation of the .NET runtime, C# compiler, and JScript compiler from Microsoft.