Ask HN: State of WASI
3 bgwalter 2 5/21/2025, 9:24:14 AM
What is the state of WASI vs. emscripten? I have tried wasmtime (which downloaded more than 400 crates to build) with wasi-libc, only to hit this issue:
https://github.com/bytecodealliance/wasmtime/issues/8068
With emscripten, which can package the required files instead of accessing the file system. everything just worked.
But emscripten is occasionally described as "unmaintained".
I'm Syrus, from Wasmer. I think the people from the Bytecode Alliance are still working on WASI, but are currently fully focused on WASIp3.
WASIp3 faces the same issues as normal WASI when compiling C libraries and apps: no thread or signals support, lacking compatibility with most of POSIX, with the added challenge that it also breaks compatibility with the original WASI.
At Wasmer we have been working on WASIX, which is a superset of WASI and adds support for the mentioned features: threads, signals, forking, subprocesses... and makes most of programs compile to Wasm easily (like Emscripten). The only con is that Wasmer is currently the only runtime that supports it (although we would love to have integration in more!).
We have been able to compile bash, CPython, PHP and many more running successfully without limitations.
Feel free to take a look here: https://wasix.org/