On an adjacent note, the work being done/posted by Collabora motivated me to try to get Mesa + Gallium soft pipe working with emscripten. Here is a demo of the classic glxgears: <a href="https://martinmullins.github.io/mesa-softpipe-emscripten/" rel="nofollow">https://martinmullins.github.io/mesa-softpipe-emscripten/</a>