Side note: I purchased Interix and used it to port a million-line C++/X11/Motif/OpenGL app to windows (successfully, although there wasn't really any demand for the result). Must have been '96 or '97. I didn't find it compelling, and the authors of the code decided to rewrite a new system from scratch, using Python and Tk (along with C++ and OpenGL) to be portable to all the commonly used platforms. That worked on Windows, Linux, IRIX, and later Mac OS X for at least 2 decades(!) with very little platform-specific code (except in the Tk dependency). They finally switched to Python/C++/Qt/OpenGL a few years back which I expect will work for another 20 years.