I wrote an Atari ST emulator out of nostalgia called STonX myself when I started to use a Unix box (Sun IPC), I believe it was the first open source ST emulator

I wrote an Atari ST emulator out of nostalgia called STonX myself when I started to use a Unix box (Sun IPC), I believe it was the first open source ST emulator ('94 or '95, also the first for Unix with big/little endian support, ran on Linux, DECstations with Ultrix, Sun/Solaris etc.). It was somewhat special in that it supported "native" graphics capabilities, i.e. bigger resolutions than 640x400 using VDI if the host hardware supported them. Had a bunch of bugs though that I never got round to fixing... My memories of the ST were fond: it was quite powerful yet still a system that you could look into every aspect of, you could single-step through the OS in ROM if you wanted and there weren't dozens of strange tasks running all the time like today. When MiNT (Unix-like OS layer) was released, we could even play in the Unix league using gcc, bash, tcsh, emacs.