I think these sites are quite interesting... so I want to know how they creat it... For example Filestube.com or Ligga.net , etc.
You mean the forums? They use Vbulletin for the forums. Or do you mean "those" sites. You werent that clear. I have no idea what those sites use as there script. Kind of weird for having this as your first post.
What do you mean? script or the system? if script i can see html there. but for dynamic website like that mostly they use php. Actually there are lot of CMS that is free you can try out to create a great website.