[lbhdc]

It is a runtime for wasm. Wasm is not executable in the same way an x86 binary is. It needs to run in a vm. Wasmtime is one such vm. In a browser context that vm is v8.

https://github.com/bytecodealliance/wasmtime

[egberts1]

Or for Firefox, SpiderMonkey JIT.

V8 is a chrome-specific thingie.