Debian is a popular Linux release, which is used mainly on PC's, but a lot of people have begun using it lately as a web server OS as well, because of the stability and protection it provides. The latter is a direct result the fact that Debian is developed and supported by thousands of qualified volunteers around the globe, so any patch that is necessary to fix a certain issue is released within a few days. The same community can also help you with any question or issue that a user may ever have, due to the fact that they can be contacted through electronic mail using e-mail lists and a qualified response will be sent in around 15-20 minutes. The advantage here is that your queries will be addressed by the same people who have designed the Operating System itself and they have an in-depth knowledge of how it works. As Debian is absolutely free, you will not 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 as well as the 30.000+ software packages that are available for it.