Tarrasch is a simple computerized chess workbench. Use it to play against the computer, analyze positions, create and edit chess documents.
Tarrasch is intended to be simpler than any other chess GUI to use. Tarrasch doesn't restrict your freedom. Move the pieces around the board, setup any position, start playing against the engine of your choice with either color from any position at any time. Change the clock settings at any time, go ahead, give yourself a nice time handicap against the engine! You can even set the clocks to be visible and running when you're not playing the engine, that way the GUI serves as a simple board, men and clocks for a game against a real human opponent.
The simplicity and freedom of Tarrasch doesn't mean there are no powerful features. Tarrasch can use any .pgn file as an opening book. Tarrasch has an 'open book' philosophy, so you can see the book moves available at any time and you can tell when the engine has played a book move. Tarrasch will optionally prompt you with the book moves available if you choose a non book move. This feature, inspired by Reptor (an earlier Triple Happy program - still downloadable and described in the FAQ) helps you memorize opening moves.
The .pgn book that comes with Tarrasch includes training positions. It is very easy to setup any of these training positions and work on your technique by practising against an engine from the training position. Tarrasch will remind you of the book move if you stray from a path stored in the .pgn book.
Tarrasch makes it very easy to create your own .pgn files, so coaches can use Tarrasch to create their own training exercises for pupils.
Tarrasch has full or partial blindfold modes, and a 'play N half moves behind' mode. These innovative training features are designed to help improve your ability to see ahead. The Tarrasch Toy Engine is an ideal opponent using these modes (you don't really want to handicap yourself when you're playing a strong modern engine!).
Tarrasch's "swap sides" feature is designed to make playing against a strong engine more fun. When you get that sinking "this is hopeless" feeling, just swap sides! The engine will often find a way to fight its way back into the game. If not, you can practise converting a winning advantage.
Recent versions of Tarrasch have great facilities for creating and editing chess documents. Like everything else in Tarrasch, these features are easy to use. Just click anywhere in a game and play alternative moves to start variations. Just click anywhere and start typing to enter and edit comments (annotations). You can easily promote and demote variations, and even convert moves to comments and vice-versa. This is a great way of fixing slightly damaged chess documents that other chess programs choke on. You can paste chess text copied from websites and convert the text to a real chess document.
Another innovative Tarrasch feature is kibitz capture. The kibitzer is Tarrasch's name for automated analysis from the engine. To analyse a position in a game, just click the "robot" symbol to start the engine thinking. Once the engine has produced some potentially interesting lines, "capture" them with one button press and the lines are entered into your workspace as variations. You can then play through them at your leisure. Like everything else in Tarrasch, this is undoable, if you don't need the lines "undo" and the document will revert to the state it was in before you captured the lines.