GoldenCheetah is a software package that:

Downloads ride data directly from the CycleOps PowerTap and the SRM PowerControl V, VI and VII.
Imports ride data downloaded with other programs, including TrainingPeaks WKO+ and the manufacturers' software for the Ergomo, Garmin, Polar, PowerTap, and SRM devices.

Provides a rich set of analysis tools, including a critical power graph, BikeScore calculation, histogram analysis, a best interval finder, and a pedal force versus pedal velocity chart, to name just a few.
Is available for Linux, Mac OS X, and Windows.
Is released under an Open Source license.

We believe that cyclists should be able to download their power data to the computer of their choice, analyze it in whatever way they see fit, and share their methods of analysis with others.