Debian is a Linux release, that's preffered for desktop computers, however it's been gaining popularity as a server OS over the last few years as well. It is very stable and secure, because fixes are released within a few days after a problem is discovered. Debian has a large support community, so when you have any kind of questions or issues with the OS or with any of the 30,000+ packages it is equipped with, you can contact the developers without delay through email using special e-mail lists and receive a reply in 15-20 minutes. The Debian community provides the best level of support possible, because all your questions will be handled by the same people that built Debian in the first place, so they have a detailed knowledge of how their system works. As the Operating System is absolutely free to use and distribute, no license charges will be added to your website hosting fees and you'll be able to change the code files and any other software which you install without restrictions, in order to optimize the software environment for your web sites. In addition, Debian performs very well on any kind of hardware, because it is light and effective and doesn't require much memory.