Those interested in this should check out Pyodide[0]. It basically "just works" so long as the libraries you import are pure Python or are part of the core scientific stack (the Pyodide authors have done the work to manually port all the C code behind numpy, scipy, etc.).

What I really wish for is for ~all Python packages to work in the browser without manual porting of the underlying C/Rust/etc. being needed, since a lot of the interesting and useful libraries aren't pure Python, and manual porting is non-trivial.

I'm not sure what the best route to that future is, but I'm guessing it'd probably help if Python had a wasm runtime in its standard library[1], since then authors of libraries that use C/Rust/etc. might make cross-platform builds (perhaps by default).

Regarding this Pycon speech, it seems that it's related to the following entry in the 3.11 changelog[2], which the speaker was heavily involved with:

> CPython now has experimental support for cross compiling to WebAssembly platform wasm32-emscripten. The effort is inspired by previous work like Pyodide. (Contributed by Christian Heimes and Ethan Smith in bpo-40280[3])

But maybe Christian has more to reveal here? In any case, I'm hugely appreciative of all the work that is being done to bring Python to the browser!

[0] https://github.com/pyodide/pyodide

[1] https://discuss.python.org/t/add-a-webassembly-wasm-runtime/...

[2] https://docs.python.org/3.11/whatsnew/3.11.html

[3] https://bugs.python.org/issue40280