Always remember, however, that there’s usually a simpler and better way to do something than the first way that pops into your head.

Beware of bugs in the above code; I have only proved it correct, not tried it.

Meta-design is much more difficult than design; it's easier to draw something than to explain how to draw it.

... the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. ... If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important.

Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%.

My general working style is to write everything first with pencil and paper, sitting beside a big wastebasket. Then I use Emacs to enter the text into my machine.

We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.