+Building a VM for Retro can be pretty easy.
+ cp vm/complete/retro.py retro
+ cp vm/complete/retro.rb retro
+The C implementation can be built easily as well. You'll need GCC and Make:
+OSX users can get the needed tools as part of Xcode. On Windows I've built this under Cygwin, MinGW, and TinyCC.
+(As a side note, if you modify the CC variable in the Makefile, you can also build with clang)
+For users of .NET, compile either vm/complete/retro.fsx (F#) or vm/complete/retro.cs (C#). These can be compiled with either Mono or Microsoft's .NET implementations. For Mono, try:
+ gmcs vm/complete/retro.cs