The Unarchiver didn't used to be proprietary, it used to be LGPL. Coincidentally just a few days ago I was looking to see if anyone had forked the last LGPL ver

The Unarchiver didn't used to be proprietary, it used to be LGPL. Coincidentally just a few days ago I was looking to see if anyone had forked the last LGPL version but I didn't look very hard and didn't find anything. If it's still floating around, you could start there. Edit: This appears to be the source code of the old LGPL version: https://cdn.theunarchiver.com/downloads/TheUnarchiverSource.zip https://cdn.theunarchiver.com/downloads/TheUnarchiverSource....