Extensions?

Seeing the 'Embrace, extend, extinguish' posts it has made me wonder as to whether Microsoft have added 'extensions' to the language to make the code incompatible with anything other than .Net? Has this happened with IronPython? I wonder because this is exactly what they did to C++ and a host of other things. Can this be confirmed?

And what is with the Iron'Crap'? It just makes me think that they have extended it into new super dooper (but slightly buggy - don't worry it is fixed in the next version of .Net) Windows only Ruby/Python.