ResEdit

ResEdit is probably the most used tool/utility in the world of programming. It is used to manipulate and create resource forks and can also be used to extract pictures, text, icons etc. that may by in a program's resource fork. Be careful though, if you don't know how to use this utility written by Apple, you probably don't want to mess with the original copies of files you edit or you will probably end up with a unusable file.