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CentOS is unique among widely distributed operating systems in that it closely mirrors (in both performance and stability) one of the most successful Linux enterprise distribution, Red Hat, while remaining free of charge. This is accomplished by "outsourcing" support to the user base. In 2010 it replaced Debian as the leading Linux OS for web servers worldwide and has seen increasing adoption as the preferred framework for computer science education.
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Pros
Pro Greatly favours stability over anything else
CentOS favours stability over being up-to date. For this reason it ships with packages that may be up to two years behind in order to ensure stability over everything else.
Using older versions for packages means that they have been thoroughly tested and used in production for quite some time, and are ensured to play well with each-other.
This strategy has paid off quite a lot in the past. One example is the Heartbleed bug which left CentOS unaffected since it was using a two-year old OpenSSL library which did not have the bug.
Pro Built-in disaster recovery solutions through clusters
CentOS has several built-in solutions for disaster recovery. For example, it comes with pacemaker which can be configured to manage multi-site and and stretch clusters across multiple geographical locations for disaster recovery and scalability. It can also be configured to trigger notifications when the status of a managed cluster changes by using enhanced pacemaker alerts.
Pro Applications don't have to take into account potentially breaking changes in libraries
Since CentOS backports all updates and bug fixes to older versions in order to maintain package compatibility across releases, applications hosted on Red Hat Linux don't have to worry about potential breaking changes in libraries they use, especially language libraries.