A file extension, or file name extension, is the letters immediately shown after the last period in a file name. For example, the file extension.txt has an extension of .txt. This extension allows the ...

TUAW reader David wrote us to ask how he could view .erb files (Rails development) in Quick Look. The fact is, there are a lot of plain-text files with extensions that Quick Look doesn't recognize. It ...

I recently upgraded to Windows 8. Why do files no longer include letters after a period at the end of their names? I used to see file names that ended with .doc and .xls, and even longer names like ...

When you double-click on a file in Windows XP, the operating system will automatically open the file using a program that has been is associated with the file's extension. It is possible, though, to ...