FreeCAD Runs in Your Browser: A Massive CAD Port to WebAssembly

FreeCAD in the Browser

I successfully ported FreeCAD, a massive parametric 3D CAD application with over 1.5 million lines of code, to run entirely in a browser tab. Using Qt for WebAssembly and JSPI, this feat took just four days with the help of Fable, an AI agent. The result is a fully functional, scriptable CAD kernel and GUI that runs on modern Chromium browsers, proving that even complex desktop applications can scale to the web.

"It is roughly an order of magnitude larger than the other two — about 1.5 million lines of C++ and 700 thousand of Python — and it now runs in a browser tab."