Debian is a Linux release, that's widely used for desktop machines, but it's been gaining popularity as a server Operating System over the last couple of years as well. It is very dependable and safe, as fixes are released in a couple of days after an issue is discovered. Debian has a vast support community, so when you have any questions or troubles with the OS or with some of the 30,000+ packages it is equipped with, you're able to contact the developers right away through e-mail using special e-mail lists and receive a reply in 15-20 minutes. The Debian community supplies the best level of support possible, because all your questions will be handled by the same people that made Debian in the first place, so they have a thorough knowledge of how their system works. Because the Operating System is 100% free to use and distribute, no license costs will be added to your hosting fees and you can modify the code files and any other software that you install with no restrictions, to optimize the software environment for your websites. What's more, Debian performs really well on any hardware, as it is light and effective and does not require a lot of memory.