The cost of adding a feature isn't just the time it takes to code it. The cost also includes the addition of an obstacle to future expansion. ... The trick is to pick the features that don't fight each other.

Programming in the abstract sense is what I really enjoy. I enjoy lots of different areas of it... I'm taking a great deal of enjoyment writing device drivers for Linux. I could also be having a good time writing a database manager or something because there are always interesting problems.

It's nice to have a game that sells a million copies.

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.

Honestly, I spend very little time thinking about past events, and I certainly don't have them ranked in any way. I look back and think that I have done a lot of good work over the years, but I am much more excited about what the future holds.

I really think, if anything, there is more evidence to show that the violent games reduce aggression and violence. There have actually been some studies about that, that it's cathartic. If you go to QuakeCon and you walk by and you see the people there [and compare that to] a random cross section of a college campus, you're probably going to find a more peaceful crowd of people at the gaming convention. I think it’s at worst neutral and potentially positive.

An interesting question: is it easier to motivate a learned individual that never does anything, or educate an ignorant individual that actually produces things?