Debian is an Operating System which uses the Linux kernel. Although it is usually set up on personal computers, it's being used on a growing number of web servers too. The reason is that it is very stable, so a server running it will not have to be restarted for months. Debian is also regarded as being among the most safe Operating Systems you can get, as security patches are released within days after a problem is found. This is possible since thousands of experienced developers are working 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 by using special e-mail lists and respond within twenty minutes to any question. In this light, you'll 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 among the Linux distributions with the highest number of packages - more than 30,000. Since the Operating System costs nothing to use, you can modify both the core as well as all the packages in any way you see fit. Furthermore, you won't have to pay any license fees.