You can prematurely optimize maintainability, flexibility, security, and robustness just like you can performance.

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.

The important point is that 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. Sure, any given feature list can be implemented, given enough coding time. But in addition to coming out late, you will usually wind up with a codebase that is so fragile that new ideas that should be dead-simple wind up taking longer and longer to work into the tangled existing web. The trick is to pick the features that don't fight each other.

It's a good thing Doom 3 is selling very well.

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.

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.

The speed of light sucks.