Debian is a Linux distribution, that's widely used for desktop computers, however it has been becoming more popular as a server OS during the last few years as well. It's very stable and secure, because fixes are released within a couple of days after a problem is discovered. Debian has a vast support community, so if you have any questions or issues with the OS or with any of the 30,000+ packages it is equipped with, you can easily contact the developers directly via email using special e-mail lists and receive a response within 15-20 min. The Debian community gives you the best level of support possible, as all of your questions will be handled by exactly the same people that created Debian in the first place, so they have an in-depth knowledge of how their own system works. As the Operating System is 100% free to use and distribute, no license costs will be added to your hosting fees and you will be able to customize the program code files and any other software which you install without restrictions, so as to optimize the software environment for your Internet sites. What's more, Debian performs very well on any hardware, as it's light and effective and doesn't need much memory.