Originally, an Apple Lisa computer was used to develop Macintosh software. A Pascal compiler that ran natively on the Mac came later.
>Macintosh development in the early days (circa 1983-1985) was done using the Apple Lisa computer and its Lisa Workshop development environment.
The Lisa Workshop hosted a command line interface which accessed a wonderful mouse based editor, a Pascal compiler, a 68000 macro assembler, an object file Linker, the RMaker resource compiler utility program, and the MacCom Lisa-to-Macintosh utility communications program.
It had a nice programming interface to the functionality described in Inside Macintosh.
It still does: