As an experiment with Ghidra, I successfully decompiled an old Atari ST game Night Crawlers to C, made it work in all resolutions and refactored it into C++.
I noticed Atari ST Logo had strange bugs on TOS 1.4 and later, so I decided to dive in and fix it. It now runs on all TOS versions and in extended resolutions. You can use it in a browser here.
In the process of fixing ST Logo I wrote some GEM VDI/AES bindings tailored for modern optimizing compilers, which I have expanded into slimgem, which I now use for all my GEM applications.
Being deep into GEM development at this point, I decided to check on FreeGEM, the MS-DOS implementation of GEM, and it seems to be a dead project. No code changes yet but I made a turn-key FreeGEM install for DOSBox here.
I have been working on CurdleST, a wordle clone for Atari ST and FreeGEM that can run as a desk accessory. Not yet released, but as an outgrowth I wrote curdle, a testbed for core wordle game logic distilled to a minimum of portable C. You can play it online by connecting to firstname.lastname@example.org via SSH.