I love seeing projects like this. When Pyiodide came out I was excited but it was a bit difficult to use, this looks and feels fantastic.

I really like Observable as well, but I've found it difficult to find robust and broad numerical libraries in javascript like what Python has.

I would love for this type of tool to redefine how we do science. It would be amazing if many scientific papers included both their data and the code in an interactive environment with zero installs and configuration. Plus when discussing a paper you could "fork" it and explore different analysis options live which for many fields would be totally feasible to do in the browser.