I'm his grandson, not his colleague, so far be it from me to say he was a great man, but he was a great grandfather and an inspiration. He taught me an enormous amount, from logic to just how hard it can be to get people to adopt new technologies -- he eschewed word processing, writing every document directly in PostScript even up to the present -- but most importantly he showed me how important it is to love what you do, and for that I owe him a ton of my happiness and career.
Fare you the hell well, Gramps.