Debian is a Linux distribution, that's widespread for desktop machines, yet it's been becoming more popular as a server OS over the last couple of years too. It's very dependable and risk-free, since fixes are released in just a few days after a problem is discovered. Debian has a huge support community, so when you have any questions or issues with the OS or with any of the 30,000+ packages it is equipped with, you will be able to contact the developers straight away via e-mail using special e-mail lists and receive a response within 15-20 minutes. The Debian community offers the best level of support possible, since your questions will be handled by the very same people that created Debian in the first place, so they have a detailed knowledge of how their own system operates. Since the Operating System is 100% free to use and distribute, no license costs will be included with your website hosting fees and you'll be able to change the code files and any other software which you install without restrictions, so as to optimize the software environment for your websites. In addition, Debian performs very well on any kind of hardware, as it is light and quick and does not need a lot of memory.