The Linux OS.. well what more can I say. It appear to be gathering more and more stream because of its openness and also probably due to the price tag (mainly it is all free). The only really problem with Linux is that if you are coming from a Windows world then it is finding those allusive applications that you have always used and are used to as well. Hopefully on this website you can view and see what the other alternatives, which brings me to the other problem, there could be a couple alternatives that fit the role as well, so which one do you pick. But with most of the applications being free then it is not hard to check them out and see what fits your role.
Anyway, back to the Linux Operating System. It was designed by Linus Torvalds whom was a Unix man and hence why most of the commands and also structure of the Linux directories are as they are.
An Operating System mainly does everything under the scenes and allows the user communicate with the underlying hardware with really getting there hands that dirty, of course using the command line may feel like getting your hands dirty but on the whole it is not.
Linux fits this role by allowing other applications do what they do best e.g. web server without worrying about the underlying hardware, or even a GUI interface (like Windows) Gnome/KDE. I personally prefer KDE over Gnome (flame warm starts!), which again could be another problem with the free movement allot of people support what they prefer and this may come to a issue later on, but only for the hardened of computer users, on the whole most people probably do not care and as long as they can view a website (facebook) and do some documents they are happy.
So Linux is the glue that fits most of the other things together and in my opinion it does a very good job, which is why I prefer to use it over other operating systems.