First there was Eight Off, a classic game in which there are eight free cells that can be used as temporary storage, and only kings may be used to fill empty spaces in the tableau.
C.L. Baker's Baker's Game followed, reducing the number of free cells from eight to four, but allowing any card to be used to fill empty spaces in the tableau.
Paul Alfille took the concept one step further, allowing cards to be built within the table in alternating colors, as in familiar games such as Canfield and Klondike (as opposed to Baker's Game, which only allowed tableau building in suit.
The result is a little game you might have heard of, called FreeCell.
Paul also wrote the first computer version of FreeCell for the PLATO educational computer system in 1978.
See also: Interview with Paul Alfille
