Debian is an Operating System which uses the Linux kernel. Although it is usually set up on desktop 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 regarded as being one of the most protected Operating Systems to choose from, since security patches are released within days after an issue is found. This is possible because thousands of well-trained developers are part of the Debian project on a voluntary basis and not only do they work on the OS itself, they also provide 24/7 support via special mailing lists and respond within twenty minutes to any kind of question. In this light, you'll 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 one of the Linux distributions with the highest number of packages - over 30,000. Since the Operating System costs nothing to use, you'll be able to modify both the core and all the packages in the way you see fit. In addition, you won't need to pay any kind of license fees.