Kurt Godel
Alan Turing
Donald Knuth
Of course, it is a bit presumptuous to include Dr. Knuth in that list. He is still alive and working in computer programming (as a professor). Some others who are still alive and working (but who seem destined to become “historical figures” after retirement (and death) might be:
Rob Pike
Robert Griesemer
Ken Thompson
Bjarne Stroustrup (although I hate C++ myself, it is impossible ignore his
historical significance)
Niklaus Wirth
And of course a good list goes on and on: Dennis Ritchie, James Gosling, Guido van Rossum, Alan Kay, the 3 guys awk was named for: Aho, Weinberger, Kernighan...and so forth.
Computer programming is young; we are still blessed with the presence of many
pioneers, from among whom will come the short list of those who will be recognized as “great historical figures” in the programming world.