Extending through wasm sounds very appealing as it doesn’t impose a specific language while being more efficient and platform-independent unlike POSIX (not to mention sandboxing).
I hope the project goes far.
“WASM” is short for WebAssembly, a low-level virtual machine designed to be secure and easy to implement on top of production-quality JavaScript VMs like Chrome’s V8 and Firefox’s Spidermonkey. However, because it’s designed to be low-level, portable, and easy-to-optimise, it doesn’t actually have hard dependencies on any part of the web-stack - lots of people have written WASM runtimes, from simple interpreters to hyper-optimising JITs.