How a $35 PC is catching on

February 28, 2013, 1:51 PM UTC

The Raspberry Pi is a personal computer at its most Zen: motherboard, memory, connectors, and not much else. Named after the Lilliputian berry, the bare-bones Pi is the brainchild of British chip architect Eben Upton, who was inspired to get cheap PCs into the hands of would-be programmers. But the Pi, which is sold by Upton’s nonprofit, has become a hit with do-it-yourself techies. “It appears that we’ve gotten to a million units inside our first year,” says Upton. “It’s staggering.”

How it works

Upton and colleagues from the University of Cambridge’s Computer Laboratory kept cost in mind, designing a powerful but inexpensive computer. Out of the box, the Pi can be hooked up to a monitor, mouse, keyboard, and memory card (to store data). An Ethernet port connects it to the web. From there, budding programmers can start writing code in the widely used Python language.

Who is using it

Though it was created to get the young interested in code, adults with engineering chops have flocked to the device. Users have jury-rigged the Pi into voice-activated garage-door openers, automated guitar tuners, even smart pet feeders. Ultimately, Upton hopes popularity with the public will goad schools into bringing more of the devices into classrooms.

The competition

The Pi is the poster child for a renaissance in DIY computing akin to the PC fairs of the early 1980s. (They eventually led to the development of the first Macintosh.) The Arduino computer, for example, is a less powerful competitor. Another single-board computer — dubbed the BeagleBone — packs more power but sells for about $90.

This story is from the March 18, 2013 issue of Fortune.