ChronoJump is a complete multiplatform system for measurement, management and statistics of the jump events.

Chronojump uses a contact platform suitable for two events (in-platform, out-platform), and also a chronometer printed circuit designed ad-hoc in order to obtain precise and trustworthy measurements.

The flight time of a jump is an indicator of the elevation of the Center of gravity of the jumper (as long as the starting and arrival position are the same). 

ChronoJump can also be used for timing races even with intervals.

Chronojump is Free GPL'd software and hardware.

Chronojump works on GNU/Linux and Windows

All info in Chronojump website:
http://www.chronojump.org