Helping people directly can be a noble thing. Forcing other people to do it with great inefficiency? Not so much. There isn’t a single thing that I w… - John Carmack

The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying.

Sharing the code just seems like The Right Thing to Do, it costs us rather little, but it benefits a lot of people in sometimes very significant ways. There are many university research projects, proof of concept publisher demos, and new platform test beds that have leveraged the code. Free software that people value adds wealth to the world.

I think a lot of people may take some heart from this: a lot of the math, the heavy math in projective geometry, [...] took me a long time. There were many many years, a decade, when I was considered this graphics guru genius, when I really couldn't do from scratch [...] the mathematics that underpins a lot of that. But slowly, eventually, with a couple decades of experience, most of it did eventually sink in on me.