Tetris (, pronounced ) is a Russian tile-matching puzzle video game, originally designed and programmed by Alexey Pajitnov. It was released on June 6, 1984, while he was working for the Dorodnicyn Computing Centre of the Academy of Science of the USSR in Moscow. He derived its name from the Greek numerical prefix tetra- (all of the game's pieces contain four segments) and tennis, Pajitnov's favorite sport.