CentOS --http://www.centos.org
The CentOS Linux distribution is a stable, predictable, manageable and reproduceable platform derived from the sources of Red Hat Enterprise Linux (RHEL).
Corel --http://linux.corel.com
Corel supports the Linux community and is committed to developing products for the Linux operating system, including Corel LINUX OS, Corel's Linux distribution; WordPerfect Office, Corel's office suite; and CorelDraw, Corel's graphics suite.
FreeBSD --http://www.freebsd.org
an advanced operating system for x86 compatible, DEC Alpha, and PC-98 architectures. It is derived from BSD UNIX, the version of UNIX developed at the University of California, Berkeley
Mandrake Linux --http://www.linux-mandrake.com
friendly Linux Operating System which specializes in ease-of-use for both servers and the home/office. It is freely available in many languages throughout the world
openSUSE.org --http://www.opensuse.org/
The openSUSE project is a worldwide community program sponsored by Novell that promotes the use of Linux everywhere. The program provides anyone with free and easy access to the world's most usable Linux distribution, SUSE Linux
RedHat --http://www.redhat.com
is the destination for Linux, Embedded Linux, and open source solutions. We provide Linux-based support, documentation, downloads, training