Debian is an Operating System which uses the Linux kernel. Although it is usually installed on personal computers, it is being used on an increasing number of web servers too. The reason is that it is very stable, so a server running it won't need to be restarted for months. Debian is also considered to be among the most protected Operating Systems nowadays, due to the fact that security patches are released within days after a problem is found. This is possible because thousands of well-experienced developers work for the Debian project on a voluntary basis and not only do they work on the OS itself, in addition, they provide 24/7 support via special e-mail lists and reply within 20 minutes to any kind of question. In this light, you will enjoy an outstanding level of support directly from the developers who know their own platform in detail, and not from a third-party support team. Debian is also among the Linux distributions with the highest number of packages - over 30,000. Since the Operating System is completely free to use, you're able to modify both the core and all of the packages in the way you see fit. Furthermore, you will not need to pay any kind of license fees.