I just launched Three-Body Simulator: an interactive 2D Newtonian gravity playground built with React + TypeScript + Vite:
You can experiment with classic and chaotic three-body setups (like Figure Eight and Lagrange Triangle), tweak masses/velocities/constants in real time, track energy and momentum drift, and use camera lock modes plus diagnostics to explore system behavior step by step. It runs fully in the browser, so it’s easy to jump in and test scenarios quickly.
GitHub repo: https://github.com/gcbartlett/3-body-sim
Live demo: https://3-body-sim.vercel.app/