It's an application that makes backups in realtime, and saves earlier versions of each file that you have assigned it to. It's also possible to supervise, in realtime, all of the files contained in a directory, or just those that follow a determined pattern.
File Hamster allows you to save a comment for each modification made to a file. The application alerts you to the changes via a small window on the system bar.
It's the ideal tool for programmers who want to manage different the versions of the files that make up their programs.
You to access even more features on File Hamster by adding plugins, available here.