Help required in opening a file extension on your Mac? File Opener has a complete database of OS X programs to open any file format or extension on Mac.
In the database of the website you will find thousands of popular as well as rare file extensions, and the thousands of programs that can be used to support them.
File-Extension.info will help you solve the basic issues with file extensions. If you do not know how to open an unknown file, you'll find the answer here.
FILExt.com is the file extension source. Here you'll find a collection of file extensions; many linked to the programs that created the files. This is the FILExt home page.
Dotwhat.net is a file extension resource website containing detailed information on a huge number of file extensions, such as the software used to create and open files.