The OP was quoting the 8bitworkshop page which has an environment, now, for programming the Apple ][+ in the manner decribed.
I spent a few minutes on 8bitworkshop and honestly, it's kind of exciting to think of coding the APPLE ][ in C.
I think it was the mid 1990s before I saw my first color-coding editor (Metrowerks?). All this for an Apple is just fantastic.