CentOS

http://linux.softpedia.com/get/System/Operating-Systems/Linux-Distributions/CentOS-906.shtml#download



CentOS is an open source, community-supported and enterprise-ready distribution of Linux based on the publicly available sources of the commercial and highly acclaimed RHEL (Red Hat Enterprise Linux) operating system.

Besides being based on Red Hat, the project is also fully compatible with the award winning enterprise Linux distribution. Key features include active development, easy maintenance, open management, community infrastructure, and open business model.

The distribution is suitable for long term use in production environments, deployed as a server. It provides users and package maintainers with a friendly and familiar environment, as well as long-term support of the core and commercial support (offered by a partner vendor).