So just Linux? No Windows, no OS X? Within Windows, you'd see that Vista (unsupported by Microsoft) and Windows 7/8/8.1 which are still supported as well as OS X (10.7/10.8/10.9) whereas the last two are still supported by Apple actively; are out there in the consumer world and actively used. I'm not going to go into the BSD's and alternate OS's (think: Haiku and the like). .