Debian is a Linux distribution, that is widespread for desktop computers, yet it's been gaining in popularity as a server OS during the last couple of years too. It is very stable and safe, due to the fact that fixes are released in a couple of days after an issue is discovered. Debian has a huge support community, so if you have any questions or problems with the OS or with some of the 30,000+ packages it comes with, you'll be able to contact the developers without delay via email using special mailing lists and receive a reply in just 15-20 minutes. The Debian community supplies the top level of support possible, since all of your questions will be handled by the very same people who made Debian in the first place, so they have an exhaustive knowledge of how their system functions. Since the Operating System is free to use and distribute, no license charges will be added to your website hosting fees and you can customize the code files and any other software that you install with no restrictions, to optimize the software environment for your sites. In addition, Debian performs really well on any hardware, as it is light and fast and does not require a lot of memory.