GeniusTrader aims to be a full featured toolbox to create trading systems and to backtest them. It is very flexible, and you can customize almost everything. It is even possible to test various money management rules.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
This version is a complete rewrite from scratch. Even the goal has
changed; instead of being general technical analysis software, it is
now specializing in the creation and backtesting of trading
systems. It features a very flexible architecture that lets you test
many combinations of trading systems.