Hierarchical Digital Circuit Simulator. TkGate is an event-driven digital circuit simulator with a TCL/Tk-based graphical editor. It supports a wide range of primitive circuit elements and user-defined modules for hierarchical design. The distribution comes with a number of tutorial and example circuits which can be loaded through the \\Help\\ menu, and the example circuits include a simple CPU, programmed to run the Animals game. TkGate has multi-lingual support for English, Japanese, French, German, Spanish, Welsh, Czech and Catalan.