For a quick intro to WASI, including getting started using it, see the intro document.
For more documentation, see the documents guide.
Here’s a quick guide to the repositories where things live:
wasi-sdk - “WASI SDK” packages for C/C++. If you want to try out compiling C/C++, this is a good place to start. “It’s just clang.”
WASI-enabled Rust - Rust Nightly builds now have built-in WASI support. To get started using Rust for targeting WASI:
rustup target add wasm32-wasi --toolchain nightly cargo +nightly build --target wasm32-wasi
wasmtime - Wasmtime WebAssembly runtime, with WASI support, as well as the WASI documentation.
Lucet - Fastly’s WebAssembly runtime with WASI support.
Everything here is a work in progress prototype, and not yet stable.