- Quantopian (http://quantopian.com/): Python based, kinda a little bit open source (backtesting only), live trades on Interactive Brokers or Robinhood. Has a big community for stocks.
- QuantConnect (http://quantconnect.com/): .NET based, more open source (includes live trading), live trades on Interactive Brokers, has a similarly sized community but the community's attention is spread to other asset types like Forex as well.
Both have numerous example algorithms you can clone and run without much trouble. An example vaguely suited to investing: https://www.quantopian.com/posts/modern-portfolio-theory-min...