I'm working on Alis Studio (https://github.com/alphatica/alis)- software to manage portfolios and research stock market ideas.
It's an MVP but perfectly usable. I needed features that I couldn't find anywhere else:
Parameter optimization with a genetic algorithm
Fuzzy optimization: randomly remove trades or whole markets and see what happens
Data mining: find rules how to exit trades sooner for better profit
Compare strategy results to random trading
Check current drawdown for statistical significance
Write trading systems in Java so I can test every idea under the sun and never be held back by some custom "scripting" language.
Of course, it's open-source. A GitHub star is much appreciated. Thanks!