Tile Matching Solitaire
This type of solitaire is played with a set of around 144 tiles. Mah Jong tiles are traditionally used, but any design on the face of the tiles is suitable, so long as the tiles come in matching sets of four.
The tiles are stacked in layers, each layer consisting of several horzontal rows of tiles. The tiles of a row rest on the tiles of the row below - each row should be the same length as or shorter than the corresponding row in the layer below.
The objective is to remove all the tiles from the layout, but they must be removed two at a time, in matching pairs. A tile is available for removal when it is at the end of a row, and is not covered by any tile in the layer above it.
This game seems to have originated as a computer game, and exists in many versions, using various tile designs and layouts. If the tiles are dealt at random there may be no way to remove all the tiles, but many computer versions are programmed to arrange every deal in such a way that a solution is possible.
This game goes by many names: popular computer versions have included Shanghai, Taipei, Kyodai and Moraff's. Vegard Krog Petersen's Solitaire Mahjongg site is a useful reference for information about these games, including their history and rules.
There are a few variants. In a type of game sometimes known as Mahjong Connect, pairs of tiles can only be removed if they can be connected by a clear orthogonal path, often with not more than a given number of turns.
From Thomas Warfield's Pretty Good Solitaire site you can obtain Pretty Good Mahjongg, a collection of solitaire games using Mah Jong and other tiles sets. It includes the well-known tile matching game where tiles are removed from a layout in pairs, and also Mah Jong tile solitaires based on Freecell, Spider and Klondike.
Mah Jong Suite is a collection of solitaire tile matching games using Mah Jong and other tiles. It includes a layout editor which lets you change the layout of any game or create your own layouts, and various facilities for tracking score statistics.
Section 12 of Tom Sloper's Mah Jong FAQ contains information about tile matching games and numerous download links.
The Solitaire Mahjongg page offers a Java tile-matching game using Mah Jong tiles.
At Mahjong Games you can play a range of online tile matching games using Mahjong tiles.
In Triple Mahjong from gamesonly.net, sets of three tiles instead of pairs must be matched to be removed.
Albert Henderson's Mahjong Solitaire site has a free online tile matching game with Mahjong tiles.
A tile matching game can be played online at meingames.de.
Game-Mahjong.com offers a range of online tile matching games with slightly unusual rules: often the removed tiles have to be connected by a clear orthogonal path.
Mahjong Heaven offers a range of free tile matching and Mahjong Connect games.