Richard Stallman is giving a keynote talk about Free Software at the Gran Canaria Desktop Summit and I am very much looking forward to hearing what he has to say. However, I just read this short post Why free software shouldn't depend on Mono or C#, and to me what it is saying seems incoherent.
On the one hand he says that:
This is not to say that implementing C# is a bad thing. Free C# implementations permit users to run their C# programs on free platforms, which is good.