There was one compiler by Greg Comeau, as well as one Project named AGNUS. As well as Atari GNU C/C++. And maybe some more. Tho, can't remember the one I used. It was for free and I only remember it crashed when the exe was bigger than 32k.
EDIT must have been .PRG, not .EXE tho :)
EDIT must have been .PRG, not .EXE tho :)