TorchRay is a simple and performant raycasting engine that runs in the browser, using modern technologies like ES7 JavaScript and HTML5 Canvas. Its simple design and clean code (We hope 😉) is ideal for learning how a raycasting engine works.
Scene maps for the raycaster are actually stored and processed as bitmap images (in any format your browser can understand, although PNG is preferred). This makes designing levels very straightforward, as you can just use your image editor of choice! We happen to use and recommend GIMP.
To get started, clone the repository and navigate to the example directory in your browser. Play around with it, look through the source code, and check out the wiki for tutorials and documentation.