The core code lives in the SerenityOS repo (which is an OS built from scratch too!): * LibWeb (HTML, CSS, SVG, Web APIs): https://github.com/SerenityOS/serenit

The core code lives in the SerenityOS repo (which is an OS built from scratch too!): * LibWeb (HTML, CSS, SVG, Web APIs): https://github.com/SerenityOS/serenity/tree/master/Userland/Libraries/LibWeb https://github.com/SerenityOS/serenity/tree/master/Userland/... * LibJS (JS engine): https://github.com/SerenityOS/serenity/tree/master/Userland/Libraries/LibJS https://github.com/SerenityOS/serenity/tree/master/Userland/... * LibWasm (WASM interpreter): https://github.com/SerenityOS/serenity/tree/master/Userland/Libraries/LibWasm https://github.com/SerenityOS/serenity/tree/master/Userland/... and the UI lives in https://github.com/SerenityOS/ladybird https://github.com/SerenityOS/ladybird and can be built for Linux/Mac/Android.