Debian is an Operating System that uses the Linux kernel. Even though it is usually set up on personal computers, it's being used on more and more web servers too. The reason is that it's really stable, so a server running it will not have to be restarted for months. Debian is also considered to be among the most risk-free Operating Systems you can get, because security patches are released within days after an issue is found. This is possible since thousands of skilled developers work 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 reply in 20 min to any question. In this light, you will receive 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 among the Linux distributions with the highest number of packages - more than 30,000. Since the Operating System is completely free to use, you can modify both the core and all of the packages in any way you see fit. Also, you will not need to pay any kind of license fees.