Question: Is there a platform that offers a free plan with unlimited backtesting and community support for developing algorithmic trading strategies?

If you want a platform with unlimited backtesting and a community to help you develop algorithmic trading strategies, QuantConnect is a great option. This open-source project lets you create and execute trading strategies on a range of assets, with backtesting that simulates fees, slippage and spreads, and a strategy explorer to find and clone publicly shared strategies. With a free plan, you get unlimited backtesting and a large community to help your project.

Another good option is AlgoBulls, which offers a free Starter Python Build Plan with unlimited backtesting. AlgoBulls streamlines the creation, execution and monitoring of sophisticated trading strategies, supporting multiple exchanges and brokers. It also offers a library of tested and validated strategy code, which can be useful for beginners and experienced users.

If you prefer a more graphical interface, Tradetron lets you create, backtest and run trading strategies without programming. It offers a free plan and other pricing tiers, as well as a web-based strategy builder, backtesting engine and social trading features. The platform supports multiple exchange and broker APIs, offering a full environment for strategy creation and management.