Possible Duplicate:
List potential applications that could open a file
How can I get the list of applications registered to open a specific file (from its path) under Mac OS X, in objective-C?
Possible Duplicate:
List potential applications that could open a file
How can I get the list of applications registered to open a specific file (from its path) under Mac OS X, in objective-C?
Launch Services Programming Guide has the information you need. But basically you can get that list multiple ways. If you have the URL to the file, you would use LSCopyApplicationURLsForURL.
For example: LSCopyApplicationURLsForURL(fileURL, kLSRolesViewer | kLSRolesEditor);