What? An IBM computer dedicated to playing chess.
Why is it in the news? In a six game challenge between its silicon self and Gary Kasparov, world champion among us humans, it has so far won once, lost once and drawn twice.
Background: Its predecessor, the quaintly named Deep Thought, saw the light of day at Carnegie Mellon University in Pittsburg (1988).
IBM started to develop Deep Thought in 1989, regarding chess as a problem vast enough to practise on with parallel processing - the careful farming out of work to other "machines"simultaneously.
Other applications of this method of handling complex problems include air traffic control and molecular dynamics.
Its basic version used a mere 250 chips and two processors on a single board, but it whizzed through second, peering with silicon wit Just 10 half moves ahead. It was regarded as fairly thick, with an international rating of 2,450, down among the more humble grand masters.
Kasparov is rated 2,775 and the first 60 players in the world cut off around 2,600.
In 1989 Kasparov played a two game exhibition match with an experimental six processor version of Thought, then capable of two million positions per second. Kasparov won.
In 1993, Thought took on Judit Polgar, and won.
Thought then romped on to become International Computer Chess Champion (1994). Enter Deep Blue . . . Blue, was something else again. Designed to out calculate. Thought by a factor 1,000, it examined over one billion moves per second.
It contained a chess specific processor chip, matching up with IBM RI SC System /6,000 for a further several hundred fold gain over poor thicko Thought.
Its latest incarnation, using a 32 node IBM SP with 256 processors in tandem, calculates 50 to 100 billion moves within three minutes, the time allowed in classical chess. Now facing Kasparov, it never nods off, can't be psyched and makes no mistakes, ever.
Whereas a human can make just one: Kasparov once boasted that no computer no matter how powerful could beat him in a regulation chess match.
Last word: Goes to Kasparov. After his last drawn game he said: "I'm just quite pleased I escaped so narrowly at the end.
It was the worst situation to get into against the computer, with an open position and being short on time."