Debian is an Operating System that uses the Linux kernel. Though it is usually set up on desktops, it is being used on a growing number of web servers as well. The reason is that it is very stable, so a server running it will not need to be restarted for months. Debian is also considered to be among the most safe Operating Systems nowadays, due to the fact that security patches are released within days after an issue is found. This is possible because thousands of skilled developers are working for the Debian project on a voluntary basis and not only do they work on the OS itself, but they also provide 24/7 support via special e-mail lists and respond within twenty minutes to any question. Thus, you will get top-notch support directly from the developers who know their own platform in detail, and not from a third-party support team. Debian is also one of the Linux releases with the highest number of packages - more than 30,000. As the Operating System is absolutely free to use, you will be able to modify both the core as well as all of the packages in any way you see fit. Also, you won't be required to pay any license fees.