"Even a Linux fan might not have heard of CentOS Linux,
but if you're a Web or other edge-server administrator I can
guarantee you know about CentOS. That's because, according to Web
Technology Surveys, in July 2010, "For the first time, CentOS is
now leading the Linux distribution statistics on web servers with
almost 30% of all Linux servers."
"What's CentOS, other than number 15 on DistroWatch's list of
popular Linux distributions? Officially, CentOS is an
"Enterprise-class Linux Distribution derived from sources freely
provided to the public by a prominent North American Enterprise
Linux vendor. CentOS conforms fully with the upstream vendors
redistribution policy and aims to be 100% binary compatible."