I was working for one of our customer who wanted to host his POSIX executables over IIS 7.0 on Windows Vista. He has .dat files which were built on an UNIX environment. He wanted use them as a CGI application hosted on IIS 7.0. Here is where the power of inter-operability of Windows comes into play. Check out the below article to know more on the Inter-Operability piece of Windows - "Subsystem for UNIX-based Applications"