With 4Shared, you have to make an account first (a free account version is okay though) to be able to download files. There are many different ones though, but it's their own choice which one they use of course. Many papercrafters use free file hosts to upload their paper models, so they don't have to have their own webspace and website bandwidth that can be very costly every month if you get a lot of traffic. 4Shared is only a file host, so it depends on the creator of the file whether it is a PDF file or a PDO, or something completely different, not on 4Shared.!
