To elaborate on my vote for Windows, we use the Greenhills C++ toolchain on Linux to compile for our 32-bit target code and also compile on Sun Solaris using the Sun Forte toolchain for our simulation and test code. Our projects for our smaller C projects with 8/16-bit micros usually use a Windows based compiler. To kick off our builds we either run the commands directly in Unix or we can do this automatically from SlickEdit using the rsh command. Unfortunately there is a bug with the Windows rsh implementation that makes that work not quite as well as it should, but it is good enough.
We use the Windows SlickEdit because most of us come from a Windows background and are comfortable there. Also it is cheaper. This causes some problems for some users when they save a file from SlickEdit/Windows through Samba to Unix and then hit compile but for some reason the date/time stamps are not quite right and the make file does not pick up on the file change. Again, this works good enough for most of the people most of the time.
Poll
