If you think that having a couple of versions of Windows is fun to support -- try Linux.

With over 500 'popular distros' to choose from -- multiplied by the number of different tools, utilities and applications tacked on to make them the least bit functional -- you have a nightmare on your hands.

Ever hear of anyone needing to 'recompile portions of the os' to get anything to work in Windows? No they can't, and no, they don't need to.