In recent times, he's done coronavirus simulations (I don't know anything else about that), and is doing AGI research.
He's also a true hacker through and through. Simply having an example like his, as a model to follow, is helping humanity. I happen to be human, and I distinctly remember his .plan files influencing my decisions in a positive way since I was 13 or so.
(The line about getting a hotel and accomplishing as much as possible in 2 days of focused effort was particularly impactful.)
Source?
Well, at least my ideas are consistent.
As for the root source, I suppose I could just ask him now. But the idea came from a slashdot post. Carmack personally responded to some criticisms of Q3 code quality, and said that he was proud of it, and that it had generated a lot of revenue for the company.
Billions may have been off by a couple orders of magnitude though. I'm no longer sure.
Maybe not too far off, though. The revenue of Q3 Arena alone was $11M. Far more valuable is Id Tech 3, the engine that was licensed by many studios over many years. Unfortunately, I can't seem to find revenue numbers on that. I wonder if it's public.
https://web.archive.org/web/20100312100358/http://www.idsoft...
5% royalties on games sold.