Debian is a widespread Linux distribution, which is used mainly on desktop computers, however numerous people have begun using it lately as a web server Operating System too, because of the stability and security it offers. The latter is a consequence of the fact that Debian is developed and supported by a large number of qualified volunteers worldwide, therefore any patch which is required to fix a particular issue is released within a matter of days. The same community can also help with any question or issue which a user may ever have, since they can be contacted through e-mail using e-mail lists and a competent response will be sent in no more than 15-20 min. The advantage here is that your questions will be addressed by the same people who have made the Operating System itself and they have a detailed knowledge of how it functions. As Debian is provided for free, you will not need to pay any license fees to use it and you can personalize it as much as you want or need. This is valid for both the Operating System and the 30.000+ software packages that are available for it.