Beowulf cluster
n. An inexpensive supercomputer-like system created from a collection of two or more desktop PCs connected by a high-speed network.

Example Citations:
Beowulf is a system that uses a parallel-processing architecture and off-the-shelf machines running Linux operating system. One machine is the server node, and distributes a processing job to all of the other machines, which are client nodes.

The total hardware cost for 24-node Beowulf cluster was $57,000 — as compared to most commercial supercomputers today, which cost between $10 million and $30 million.
—Parveen S. Thampi, “Linux Operating System: A Freeware and the Net War,” Computers Today, October 31, 1998

The Beowulf cluster gets its name from the sixth-century Scandinavian hero who was famed in verse for taking down a monster named Grendel. The computer version, which was designed to slay the monster mainframes, was invented in 1994 by Don Becker while he was at NASA’s Goddard Space Flight Center.“
—Christina Dyrness, ”Beowulf looks to slay mainframe,“ The News and Observer, October 17, 2000

Earliest Citation:
The latest Beowulf clusters installed at Caltech Los Alamos National Laboratory, and NASA Goddard Space Flight Center, are all 16 node Pentium Pro machines with configurations that reflect the specific needs of their users.
—Daniel Ridge, et al., “Beowulf: Harnessing the Power of Parallelism in a Pile-of-PCs,” Proceedings of the IEEE Aerospace, October 15, 1996

Okay, so why the name "Beowulf" for such cluster? It's clearly based on the epic poem of the same name (the oldest poem in the English language), but what's the relationship between Beowulf the superhero and Beowulf the supercomputer?

The most common explanation is the one given in the second citation. That sounds reasonable, but Beowulf clusters are designed to augment the work of supercomputers, not "slay" them entirely. A more tantalizing clue is found in the following cite:

Dr. Becker recalled that the name had been chosen by Dr. Sterling for a number of reasons, including a line loosely translated from ‘Beowulf,’ the epic Anglo-Saxon poem, that described the heroic Beowulf as having the strength of many.
—J. D. Biersdorfer, "The Secret Life of the Home Computer," The New York Times, June 8, 2000

It's likely the line that Dr. Sterling was talking about is the description of Beowulf by Hrothgar, the Danish king, where he says Beowulf "has thirty men's heft of grasp in the gripe of his hand" (translation by Francis B. Gummere):

Hrothgar answered, helmet of Scyldings:—
"I knew him of yore in his youthful days;
his aged father was Ecgtheow named,
to whom, at home, gave Hrethel the Geat
his only daughter. Their offspring bold
fares hither to seek the steadfast friend.
And seamen, too, have said me this, —
who carried my gifts to the Geatish court,
thither for thanks, — he has thirty men's
heft of grasp in the gripe of his hand,
the bold-in-battle. 
Thanks to subscriber Frank Burns for pointing me in the right direction.

By the way, if you want to learn more about Beowulf clusters, see The Beowulf Project:

Related Words: