"Recompiling Linux source code under Microsoft Windows is not
something that Microsoft would love to see, but we would, and we
have."
"Almost 4 million lines of code from the Gnome desktop and
supporting applications have been recompiled and now run under
Microsoft Windows. The effort took one person, 1.5 weeks to
complete, and required less than 100 lines of code to be
changed."
"Source code incompatiabilities between Unix based systems and
Windows leads to high cost of entry when developing for multiple
operating systems. To address these source code issues, various
porting toolkits have been suggested in the past. For Unix to
Windows based systems, there was the NuTcracker or Interix. For
Windows to Unix based systems, there was WinU."