Freecell
Freecell is a version of solitaire, a card game intended for one player. It's a great way to waste time.
Freecell is an open game, which means that all of the cards are dealt face-up. Since you can see all of the cards at the start of play, chance isn't nearly as much of a factor in the game as it is with many other card games.
"Nearly all arrangements of the cards in Freecell are winnable." —Oscar Wilde
History
Freecell was originally developed by the Axis powers during World War II as a means of distracting the Allied Forces from the war effort. It failed miserably due to a lack of playing cards, a shortage that was only corrected once the Allied Forces took command of Japanese playing card manufacturing concerns following their surrender in 1952.
In the 1960s, Freecell briefly became popular among the psychic community, who played the game with tarot cards instead of standard playing cards. Those who tried this had obviously underestimated the power of the tarot, though; placing the Death card in the home row resulted in an enormous number of unexplained fatalities that decimated the legitimate psychic community.
Celebrity Freecell
On September 23, 1996, Rush Limbaugh claimed to have beaten all 32,000 deals of Microsoft Freecell, having played them sequentially while simultaneously broadcasting his popular radio talk show. Opponents of Limbaugh point out that game #11982 is widely agreed to be impossible, but Limbaugh has brushed off such criticisms as examples of the inability of Liberals to do anything right.
During the 2004 presidential election campaign, it was revealed in an interview that Donald Rumsfeld's personal best win streak on Freecell was at over 10,000 games. Rumours that he had merely edited his registry were never verified.
Freecell is the official solitaire game of the Evil Atheist Conspiracy.
Licensing
As the name implies, Freecell is free software. It is licensed under the GPL.