Debian is a Linux release, that's widespread for desktop computers, but it's been gaining in popularity as a server Operating System during the last few years as well. It's very stable and safe, due to the fact that fixes are released in just a couple of days after a problem is discovered. Debian has a vast support community, so when you have any kind of 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 straight away through e-mail using special e-mail lists and receive a reply in just 15-20 min. The Debian community gives you the top level of support possible, because your questions will be handled by the same people who built Debian in the first place, so they have a thorough knowledge of how their system functions. Since the Operating System is free to use and distribute, no license charges will be added to your hosting fees and you can modify the code files and any other software which you install without restrictions, to optimize the software environment for your websites. Furthermore, Debian performs very well on any kind of hardware, because it's light and effective and does not need a lot of memory.