Jape is a configurable, graphical proof assistant, originally developed by Richard Bornat at Queen Mary, University of London and Bernard Sufrin the University of Oxford. The program is available for the Mac, Unix, and Windows operating systems. It is written in the Java programming language and released under the GNU GPL.
It is claimed that Jape is the most popular program for "computer-assisted logic teaching" that involves exercises in developing proofs in mathematical logic.