PyScript (https://pyscript.net/) is system for easily running Python (including numpy and SymPy) in the browser.
Here is a live demo of my “perfect” physics simulator using SymPy in the browser: https://carlkcarlk.github.io/perfect-physics/pyscript/.
p.s. I’ll be presenting “Perfect Physics” at the PyData conference tomorrow. https://seattle2023.pydata.org/cfp/talk/XS7PCB/. If you’re around, say “hi”.