Morgan,
Not true, MS has made available source for the Shared Source Common Language Infrastructure or "Rotor" as it is more commonly known.
This includes the following in source code:-
1] An implementation of the runtime for the Common Language Infrastructure (ECMA-335) that builds and runs on Windows XP, the FreeBSD operating system, and Mac OS X 10.2.
2] Compilers that work with the Shared Source CLI for C# (ECMA-334) and JScript.
3] Development tools for working with the Shared Source CLI such as assembler/disassemblers (ilasm, ildasm), a debugger (cordbg), metadata introspection (metainfo), and other utilities.
4] The Platform Adaptation Layer (PAL) used to port the Shared Source CLI from Windows XP to FreeBSD and Mac OS X.
5] Build environment tools (nmake, build, and others).
6] Documentation for the implementation.
7] Test suites used to verify the implementation.
8] A rich set of sample code and tools for working with the Shared Source CLI.
Or to put it another way "Rotor is a complete implementation of the ECMA-334 (C#) and ECMA-335 (CLI) standards in source code form". You can even test drive generics if you want to, theres an update from MS Research that allows you to do this.
http://www.microsoft.com/downloads/details.aspx?FamilyId=3A1C93FA-7462-47D0-8E56-8DD34C6292F0&displaylang=enhttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/Dndotnet/html/mssharsourcecli.aspRegards
Neil