The world has gone to shit. You need an OS that can hack it. Forget XP, Mac or your fancy Linux distros. You need Vault OS. To Summarise (from their own site)
The Vault Operating System is designed to be so cheap to implement that it can be put together mostly from junk that others have thrown away. Nobody should be prevented from building the Vault OS network by hardware costs. It is designed to use technology so ubiquitous and limited in scope that nearly any x86 third rate junk machine with the basic specs can be a client and any second rate x86 machine can be the server. It is designed to be so easy to install, maintain, modify and debug that almost anybody could do it.