ArpeggioRPG is a TTRPG (tabletop roleplaying game). Think of a game like Dungeons & Dragons or Pathfinder, but instead of needing books and character sheets, the app takes care of everything for you. It provides a tools for Game Masters to create and organize their campaigns, and a tactical combat map that makes it easy for players and the Game Master to use their abilities and skills.
MIT-licensed: http://opensource.org/licenses/MIT
To start the backend, which is implemented as a CloudFlare worker written in Rust:
cd worker
npm install
npm run dev
Then start the frontend:
cd ui
npm install
npm run dev
Hit it at http://localhost:5173/