What is CentOS? CentOS (Community enterprise Operating System), released in May 2004, is a 100% free operating system distribution based upon the Linux kernel. It is derived entirely from the Red Hat Enterprise Linux (RHEL) distribution. CentOS exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream source, Red Hat.

In July 2010 CentOS overtook Debian to become the most popular Linux distribution for web servers, with almost 30% of all Linux web servers using it. But in January 2012, it lost that position to Debian once again:

CentOS Popularity Trend

CentOS is one of the most popular Linux distributions in the hosting industry. Due to CentOS’ binary¬†compatibility¬†with RHEL, it is highly compatible with most Linux software. Most hosting control panels use CentOS as the preferred Linux distribution.

On 7 January 2014, Red Hat and CentOS announced that they would officially join forces.