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.
John CarmackMaking one brilliant decision and a whole bunch of mediocre ones isn't as good as making a whole bunch of generally smart decisions throughout the whole process.
John CarmackSharing 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.
John CarmackIn the information age, the barriers [to entry into programming] just aren't there. The barriers are self imposed. If you want to set off and go develop some grand new thing, you don't need millions of dollars of capitalization. You need enough pizza and Diet Coke to stick in your refrigerator, a cheap PC to work on, and the dedication to go through with it. We slept on floors. We waded across rivers.
John Carmack