Callisto is a vector-based space flight and combat simulator based. By vector-based this means a ship's motion is based on the physics of acceleration and velocity, with acceleration being the only tool for piloting a craft. There is no banking or rapid breaking in a vector-based system! Callisto scenarios can be populated with ships and planets. Ships can be outfitted with various weapons and sensors. Each ship enters orders and they are all resolved simultaneously. A ship's computer allows simple humans to effectively pilot based on acceleration vectors in 3D space. The heart of the computer is a nonlinear equation solver.
The code is structure in two main parts. The callisto directory contains a Rust crate containing the server and all of the game logic. It supports a well defined JSON API for communicating with the client. The fe/callisto directory contains the frontend. The frontend is a React app that uses Three.js for rendering.