Is this all open source?

I'm fascinated in learning more about how you run a web server with this - the article says "WebContainers include a virtualized TCP network stack that's mapped to your browser's ServiceWorker API" but I'd love to understand a bit more about how that works.

Since this is all done with WebAssembly are you planning on targeting other stacks such as Python? The amount of time I lose helping other people getting their Python development environments to work remains horrifying.