Karanbir Singh and Johnny Hughes have announced earlier today, October 20, on one of their Twitter accounts, that it’s been about 12 years since they first started working on the CentOS GNU/Linux operating system.

If memory serves, the first CentOS release was published as version 2 sometime in May 2014, but most probably, the developers are celebrating the birth of the project as on October 20, 2004.

In January 2014, they announced the official joining with Red Hat, the company behind the well-known Red Hat Enterprise Linux operating system, on which CentOS Linux is currently based.

http://linux.softpedia.com/blog/centos-turns-12-happy-birthday-494955.shtml