OS Supported

CentOS is a free operating system based on Red Hat Enterprise Linux (RHEL). It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution. CentOS stands for Community ENTerprise Operating System. CentOS is the most popular Linux distribution for web servers with almost 30% of all Linux web servers using it.
Official website

ALT Linux is a set of RPM-based operating systems built on top of the Linux kernel and Sisyphus packages repository. ALT Linux is developed jointly by ALT Linux Team developers community and ALT Linux Ltd.
Official website

Arch Linux is an independently developed, i686/x86-64 general purpose GNU/Linux distribution versatile enough to suit any role. Development focuses on simplicity, minimalism, and code elegance. Arch is installed as a minimal base system, configured by the user upon which their own ideal environment is assembled by installing only what is required or desired for their unique purposes. GUI configuration utilities are not officially provided, and most system configuration is performed from the shell by editing simple text files. Based on a rolling-release model, Arch strives to stay bleeding edge, and typically offers the latest stable versions of most software.
Official website

Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat. The Fedora Project's mission is to lead the advancement of free and open source software and content as a collaborative community.
Official website

Slackware is a free and open source Linux-based operating system. It was one of the earliest operating systems to be built on top of the Linux kernel and is the oldest currently being maintained. Slackware was created by Patrick Volkerding of Slackware Linux, Inc. in 1993. The current stable version is 13.37, released on April 27, 2011
Official website

openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE. After Novell acquired SUSE Linux in January 2004, Novell decided to release the SUSE Linux Professional product as a 100% open source project.
Official website

Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential Linux distribution. It is distributed with access to repositories containing thousands of software packages ready for installation and use. Debian is known for relatively strict adherence to the Unix and free software philosophies as well as using collaborative software development and testing processes. Debian can be used on a variety of hardware, from NAS devices to phones, laptops, desktops and servers. It focuses on stability and security and is used as a base for many other distributions.
Official website

Ubuntu is a computer operating system based on the Debian distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu ("humanity towards others"). Ubuntu is designed primarily for use on personal computers, although a server edition also exists.
Official website