For doing multithreading on rust/wasm32 on Chrome via webworkers, is https://crates.io/crates/wasm-mt state of the art ? (2k total downloads is making me wonder if some other library is taking most of the users)
It needs nightly Rust. That probably explains that it's not widely used.
AFAIK, thread support is conditioned by the need to recompile the std library and that keeps it in nightly for now. I'm not sure if any other wasm feature or change in wasm-bindgen is needed too. I wonder if thread support in stable is far away or not, but there's not to much activity in wasm support for the browser lately.