Great news just in: another Ambrosia classic has received an open source release. As of this week, Avara is now available as open source. There’s a lot of work that goes into creating a playable game from that (it took a year for Antares) but releasing the code is the first step.
If you’ve got the time, also check out the 20th Anniversary Livestream.
To my knowledge, there are now three Ambrosia games from the MacOS Classic era that have been open-sourced:
Aside from that, there are a couple of other projects in the open source community based on old Ambrosia games:
For even more open-source games, like Bungie’s Abuse and Marathon, see osgameclones.com.