Debian is a Linux release, which is preffered for desktop computers, but it's been gaining in popularity as a server Operating System during the last couple of years as well. It's very dependable and protected, as fixes are released within a couple of days after a problem is discovered. Debian has a huge support community, so if you have any questions or problems with the OS or with any of the 30,000+ packages it comes with, you'll be able to contact the developers right away via electronic mail using special e-mail lists and receive a response in 15-20 minutes. The Debian community offers the top level of support possible, since all of your questions will be handled by the very same people who built Debian in the first place, so they have an in-depth knowledge of how their system functions. As the Operating System is 100% free to use and distribute, no license charges will be added to your web hosting fees and you'll be able to customize the program code files and any other software which you install without any restrictions, so as to optimize the software environment for your sites. What's more, Debian performs really well on any hardware, because it is light and effective and doesn't need a lot of memory.