Which WebAssembly language/s interest you?
I just discovered AssemblyScript (portal | thread) which looks interesting!
Here are some of the more common ones:
https://kotlinlang.org/docs/reference/native-overview.html
https://fsbolero.io/docs/
https://wiki.dlang.org/Generating_WebAssembly_with_LDC
https://ziglang.org/documentation/master/#WebAssembly
Not forgetting Lumen:
Also just found:
https://run.rb and GitHub - pannous/wruby: Web Ruby : ruby running in the browser via webassembly