If you're mandating a specific OS then you're going to risk losing talent that prefers other OSes. On the other hand you will attract people that like said OS.

If you're mandating a specific OS then you're going to risk losing talent that prefers other OSes. On the other hand you will attract people that like said OS. At our place we don't give a rat's behind about what you run in a VM, but your main OS is either Windows 7 or OSX because it has to run PGP WDE or Becrypt, and neither play nice with multi-boot OSes. Having said that I know one guy in the office who just boots up his Win7 box, fires up an OpenBSD VM and does everything in there, and no-one has any problems. Virtualisation on the desktop is mostly free. Let people who have a valid business case for Windows use it, in a VM if you're uncomfortable with bare metal Windows support.