Where I see this as a huge deal is for plug-in development. For finl, I was looking at the possibility of incorporating an interpreter for JavaScript or Python or Lua. Instead, I can create bindings for WASM and get a sandboxed environment for people to write their own extensions. There will be some packaging tools that I’ll want to provide (the idea being that a user specifies something like

     \LoadExtension{yoyodyne:csv-reader:1.0}

to bring in an extension and if there isn’t a local copy of the extension, it will fetch it from a repository, and I’ll want to bundle a bunch of stuff into a standard ZIP file layout (so that documentation, etc. will be easily fetched).

The list of languages that can compile to WASM increases on a regular basis and it seems by far the best route for plugin handling in a greenfield project.