what file type is xxx?

Question

what software can i use to open a filetype "xxx"

Answer 1

http://filext.com/file-extension/XXX

Answer 2

This is not a regular extension. It is probably renamed from another file. Try to shift+right click the file and choose "open with" and try some regular type of files like:
1. txt and open with word or notepad
2. image(jpg, gif) and open with an image editor
3. avi if is more than 1 mb - could be a film
4. mp3 if is music.
5. an exe. but in this case it is not advisable executing it .. as it could be a virus (try to scan it with a antivirus)
if nothing works delete the file.

Answer 3

Type "filetype XXX" into Google and everything will be explained.