Demonstrations of Emscripten generated WebAssembly and a web worker. In the single threaded version (tsp_single_thread), running a computationally intensive WASM blocks the JavaScript main thread and stops interaction on the page. With the web worker version (tsp_worker_DOM), work happens in the background and interaction can continue unblocked. The traveling salesman problem (TSP) is used as a sample computationally intensive task.