If Unix could present the same face, the same capabilities, on machines of many different types, it could serve as a common software environment for all of them.

A security system is only as secure as its secret. Beware of pseudo-secrets.

Programmer time is expensive; conserve it in preference to machine time

Anybody who has ever owned a dog who barked when strangers came near its owner's property has experienced the essential continuity between animal territoriality and human property. Our domesticated cousins of the wolf know, instinctively, that property is no mere social convention or game, but a critically important evolved mechanism for the avoidance of violence. (This makes them smarter than a good many human political theorists.)

The beginnings of the hacker culture as we know it today can be conveniently dated to 1961, the year MIT acquired the first PDP-1.

If you treat your beta-testers as if they're your most valuable resource, they will respond by becoming your most valuable resource.

A critical factor in its success was that the X developers were willing to give the sources away for free in accordance with the hacker ethic, and able to distribute them over the Internet.