Debian is a well-known Linux distribution, which is used mainly on PC's, but lots of people have begun using it lately as a web server Operating System too, because of the stability and security it provides. The latter is a result of the fact that Debian is developed and supported by numerous qualified volunteers worldwide, therefore any patch that's required to fix a certain issue is released within a couple of days. The very same community can also help you with any question or trouble that a user may ever encounter, due to the fact that they can be contacted through electronic mail using e-mail lists and a qualified response will be sent in no more than 15-20 min. The advantage here is that your queries will be addressed by the same people who have developed the Operating System itself and they have an in-depth knowledge of how it works. As Debian is absolutely free, you won't need to pay any license fees to use it and you will be able to personalize it as much as you want or need. This is valid for the Operating System and the 30.000+ software packages that are readily available for it.