Pro Tools (Mac)

Early Pro Tools digital audio workstation software for Macintosh, versions 3-5 used a session file format which uses the Resource Fork only of the Mac's HFS file system. It was replaced with PTS Pro Tools 5.1-6.9. It is a session file which doesn't directly contain the audio data, but should be accompanied by audio files (such as SD2).

Links

 * Official site
 * Pro Tools 6.1 Reference Guide - Session Formats