Debian is an OS which uses the Linux kernel. Although it is usually set up on desktops, it's being used on a growing number of web servers as well. 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 one of the most secure Operating Systems to be found, since security patches are released within days after a problem is found. This is possible because thousands of experienced developers work for the Debian project on a voluntary basis and not only do they work on the OS itself, they also provide 24/7 support through special mailing lists and reply within twenty minutes to any question. In this light, you'll obtain 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 absolutely free to use, you're able to modify both the core as well as any of the packages in any way you see fit. In addition, you will not have to pay any license fees.