(From the book "Real Men Don't Eat Quiche") A variety of hacker possessed of a flippant attitude toward complexity that is arrogant even when justified by experience. The archetypal "Real Programmer" likes to program on the bare metal and is very good at it, remembers the binary op codes for every machine he has ever programmed, thinks that high-level languages are sissy, and uses a debugger to edit his code because full-screen editors are for wimps. Real Programmers aren't satisfied with code that hasn't been bummed into a state of tenseness just short of rupture.
Real Programmers never use comments or write documentation: "If it was hard to write", says the Real Programmer, "it should be hard to understand." Real Programmers can make machines do things that were never in their spec sheets; in fact, they are seldom really happy unless doing so. A Real Programmer's code can awe with its fiendish brilliance, even as its crockishness appals.
Real Programmers live on junk food and coffee, hang line-printer art on their walls, and terrify the crap out of other programmers - because someday, somebody else might have to try to understand their code in order to change it. Their successors generally consider it a Good Thing that there aren't many Real Programmers around any more.
For a famous (and somewhat more positive) portrait of a Real Programmer, see "The Story of Mel". The term itself was popularised by a 1983 Datamation article "Real Programmers Don't Use Pascal" by Ed Post, still circulating on Usenet and Internet in on-line form.