There were plenty of C compilers but only a couple were in common use. If I recall, Lattice C was popular. Mark Williams was another one. "Alcyon C" was includ

There were plenty of C compilers but only a couple were in common use. If I recall, Lattice C was popular. Mark Williams was another one. "Alcyon C" was included I think in the ST development kit, but was considered poor. I think people use "Pure C" these days, but of course also GCC is likely best: http://vincent.riviere.free.fr/soft/m68k-atari-mintelf/ http://vincent.riviere.free.fr/soft/m68k-atari-mintelf/ Is maintained by Vincent Rivière, who is a major contributor on EmuTOS.