We used some port floating around on sourceforge possibly, couldn't use cygwin, fully MSVC++ 6.0. Had some magic way to compile it. I also remember compiling and recompiling GNU make, and all the fun to be had with make sometimes being BSD make, GNU make, or even NMake.
Whilst I've left the company 5 years ago, my friends who still work there still use it.
My life would have been miserable otherwise.