Azure has shipped Spin as an experiment https://learn.microsoft.com/en-us/azure/aks/use-wasi-node-po... and is investing in Wasmtime and WASI https://opensource.microsoft.com/blog/2025/03/26/hyperlight-... (One author, Yosh, is the co-chair of WASI standards subgroup)

This platform is also based on wasmtime and wasmtime's wasi-http implementation, which I authored, so I'm really proud to see it reused here!

One more plug: I've been working on https://github.com/yoshuawuyts/wstd/ with Yosh and Dan Gohman (creator of WASI) as a nice way to write wasi-http guests in Rust.