http://source.winehq.org/git/wine.git/tree/HEAD:/dlls http://source.winehq.org/git/wine.git/tree/HEAD:/dlls These are all the system libraries Wine has reimple

http://source.winehq.org/git/wine.git/tree/HEAD:/dlls http://source.winehq.org/git/wine.git/tree/HEAD:/dlls These are all the system libraries Wine has reimplemented so far, and thats only up to its current near-DX10 support, and these libraries are just the base - most applications can ship their own copies of Windows libraries, but as long as the core libraries everything else depends upon work you can run other libs on top of them. But a lot of Windows has been reimplemented between the old 3.1 era and now, and not just the kernel - MS has maintained fair backwards compatibility the whole say so new versions of the same API can be dramatically different in implementation. If Microsoft wanted to support Windows executables on Unix they would need to just pick up where Wine is at now and continue their work, albeit with insider access to code to know all the edge cases of their own implementations of these APIs, since software is written against the bugs.