After joining the Labs I mentioned to Dennis that the idea of "main" did
not appear in the semi-formal specification of C in the back of the first
edition of The C Programming Language. (It obviously appears in the front
half.) He was very surprised, but maybe it's an indication that the idea of
"main" was already part of the culture. I first encountered it in the
phrase PROCEDURE OPTIONS MAIN that begins every PL/I program. PL/I was
defined in the early 1960's.

-rob