Not all servers use Windows Server or a Linux Distro, instead they may use FreeBSD. I recently got some space for an IRCd on a server with FreeBSD. I never really used FreeBSD at all until now, but I have nothing but good things to say about it. It is the most stable, fast, and reliable OS I have ever used. Since I am running an IRCd on it, it pretty much has to be stable. If you are looking to run a web server or an IRCd, I strongly recommend using FreeBSD.
