Important! What were you writing about earlier on running a full operating system in the browser? Oh yes, it was Google Native Client, NaCl, repurposed into a virtual machine. Now, it turns out that there is in fact such a project in progress for modern WebAssembly… well, sort of. Browsix.
20180924/https://browsix.org/
20180924/https://github.com/plasma-umass/browsix