So, I was disappointed to find dead links to a Windows-based emulator :-(

Does anyone know...

* What happened to the creators?

* Who owns the copyrights, if at all?

* Has anyone been approached to release the source code and games resources?

Also, if anyone has an appropriate Linux emulator, which supports these games, please share a link and perhaps instructions.

Mini vMac (bundled in the zip) has Linux versions too.

https://www.gryphel.com/c/minivmac/

Dark Castle was by Jonathan Gay, who also did Shockwave Flash, a somewhat more popular project.

https://en.wikipedia.org/wiki/Jonathan_Gay

Mini vMac. You’ll need a mac plus ROM file and a copy of the software disk images.

Or, return to dark Castle is now available on steam as mentioned elsewhere in this thread. It contains all the dark castle and beyond dark castle levels plus many more new levels and works on modern computers.