I originally developed a WASM port of wxWidgets for https://dj.app/. When it came time to open source wxWidgets-wasm, I decided to port another complex app as a test case, and Audacity seemed like the obvious choice. In the process, I also needed to write a new host API for PortAudio for playback and recording in the browser.
https://github.com/ahilss/wxWidgets-wasm
https://github.com/ahilss/portaudio-wasm
https://github.com/ahilss/wavvy