StuffIt used to be included for free with new Macs, but isn't anymore. The format was big in the System 8 and 9 days, I guess. If you need to open them, you have to use StuffIt; nothing else can read ".sit" files. For that reason, you'll probably want to avoid packaging your own stuff in StuffIt files, too. (If you need to compress something, just right click on it and choose "Create Archive", and you'll get an instant ".zip" file of it).
.sit - What must I do with that?
Miscellaneous Forums/MacOS X Discussion/.sit - What must I do with that?The forum is locked. These are the original blitzbasic.com forums, kept so they can still be read. No new topics, replies or edits can be made here. To join in, head over to the Blitz3D+ forums.