Cogent Core is a free and open source framework for building powerful, fast, elegant 2D and 3D apps that run on macOS, Windows, Linux, iOS, Android, and the web with a single Go codebase, allowing you to Code Once, Run Everywhere (Core). See the Cogent Core Website for more information, including extensive documentation and editable interactive running examples. The website itself is a Cogent Core app running on the web using wasm.