Cygwin, Gnu C++  and Microsoft Visual Studio 7 were mentioned somewhere. I believe there are quite many compiling environments for Blender. Actually had to be; many OSes.  And Python is included as scripting solution as a dynamic library (as damir_prebeg said).

There seems to be quite many modified Blender packages also, so I wouln't be surprised if you could code modifications with other languages. I don't know how Shmender and Blender2KT are implemented, for example.