A very efficient tutor.
A national virtual bridge engineering contest for kids of all ages.
robotfindskitten: a Zen simulation
Contest Evaluation software for RU-QRP Club and others
Solve 9x9 Sudoku Puzzles Using A Command Line Utility
Row&column sliding logical game
Mirror for ejudge contest management system
DOMjudge is an automated judge system for programming contests.
QRP contests simulator