Debian is an Operating System which uses the Linux kernel. Though it is usually set up on desktops, it is being used on an increasing number of web servers as well. The reason is that it is really stable, so a server running it won't have to be restarted for months. Debian is also regarded as being one of the most risk-free Operating Systems available, as security patches are released within days after an issue is discovered. This is possible because thousands of well-experienced developers are employed by the Debian project on a voluntary basis and not only do they work on the OS itself, in addition, they provide 24/7 support by using special e-mail lists and reply in twenty minutes to any question. In this light, you will have top-level support directly from the developers who know their own platform in depth, and not from a third-party support team. Debian is also one of the Linux distributions with the highest number of packages - over 30,000. As the Operating System is free to use, you are able to modify both the core as well as all of the packages in the way you see fit. In addition, you will not need to pay any kind of license fees.