ChronoJump is a complete multiplatform system for measurement, management and statistics of jump time events (contact time, flight time), and other actions. (GPL)

JDiveLog is an open source diver's logbook for logging scuba dives. It's written in Java (JRE 5.0 or later required). (GPL)

SportsTracker is an application for people which want to record their sporting activities. (GPL)