Debian is a Linux distribution, that's preffered for desktop computers, but it's been gaining popularity as a server Operating System over the last couple of years too. It is very dependable and safe, due to the fact that fixes are released in a few days after an issue is discovered. Debian has a huge support community, so when you have any kind of questions or troubles with the OS or with any of the 30,000+ packages it is equipped with, you can easily contact the developers right away through email using special mailing lists and receive a response in just 15-20 minutes. The Debian community offers the top level of support possible, as all your questions will be handled by exactly the same people that made Debian in the first place, so they have an in-depth knowledge of how their own system works. Because the Operating System is absolutely free to use and distribute, no license costs will be included with your website hosting fees and you can modify the code files and any additional software which you install without restrictions, to optimize the software environment for your websites. In addition, Debian performs very well on any kind of hardware, because it is light and fast and doesn't need much memory.