.rar? More like .
wtf? It happens to the best of us. You’ve downloaded a file only to realize (along with your computer) that you haven’t the slightest idea what to do with it or what application will open it. File Extensions tries to help you demystify that weird file extension by providing a searchable database of file extensions, what programs they are associated with, and how to use them. You can search for file extensions alphabetically, by symbol (if the three-character extension name includes one), or by number. Alternately, you can search by file type if you have some idea of what sort of file you’re dealing with. File Extensions also categorizes and displays file extensions by recently updated, most searched, and even has a “File extensions of the day” featured section. File Extensions also offers two separate overviews sections, one for common file extensions and one for unknown file extensions.
File-Extensions.org In Their Own Words
“The source for file extensions information”
Why File-Extensions.org It Might Be A Killer
This is an extremely useful site for anyone who has ever received those infuriating “Windows does not recognize…” error messages or the equivalent on other platforms. It provides relevant information about not only the file itself, but also the program that created it and what applications you can use to open and modify it.
Some Questions About File-Extensions.org
The site itself could benefit from a little housekeeping; searchable sections should be grouped together and the interface could be made more streamlined by reducing overly-long lists of files. 
