25th Anniversary of Tetris

Source: http://www.google.com/logos/tetris09.gif
Tetris (Russian: Те́трис) is a puzzle video game originally designed and programmed by Alexey Pajitnov in the Soviet Union. 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, known as Tetrominoes, contain four segments) and tennis, Pajitnov's favorite sport. [Read more on Wikipedia]