Well, we know that Brutal Deluxe
the French GS development group kind of come out retirement a few months ago but I had thought they had only woken up long enough to post their old stuff and information.
That's not entirely correct. They (in particular Antoine), have gone nuts and have started writing FST (File System Translators) for GS/OS. Even Apple didn't really finish the ones they've done but BD have got an rDOS (a custom OS used for copy protection by some companies) and some other FST's - Like CP/M - working. The trick that they've been trying to figure out is how to make 13 sector (and even a custom 10 sector) format disks usable from inside GS/OS.
Keep an eye on them - you can also check out a HUGE amount of their older stuff for GS and Apple //s at their site - Brutal Deluxe
I forgot to mention that Antoine has some articles running in Juiced GS
. You do know what Juiced GS