OTL Checkmate is a smart and modern open source chess font. The font is based on contextual alternatives ('calt'), which allows it to automatically solve some routine tasks when typing chess game diagrams. Thanks to the 'calt' feature, the font automatically arranges the color cells of the playing field, and is able to put the figure on the cell of the desired color. This significantly speeds up the typing. Plus, the feature allows you to display some elements of the playing field frame automatically.