A Windows desktop application facilitating chess training.

Its key differentiating feature is a special training mode where users can test themselves against a Variation Tree, a Game or en Exercise. The program will assess user's moves against the content and the comments in the Workbook. It also allows users to evaluate any move with the chess engine and to verify their understanding of the studied positions by playing against the engine from any position in the Workbook.

A Workbook is a text file containing a variation tree in the extended PGN format. Workbooks can be prepared by 3rd parties (e.g. chess coaches) or by the users themselves.