It says it runs compiled .wasm binaries, which should mean any language. I think the listed languages are those targeted for interoperability.
Re:Universal Binaries Using WASM
by syrusakbary on Tuesday February 26, 2019 @03:51AM
(#19252898)
That's right.
Wasmer executes any wasm binary, including AssemblyScript generated ones :)
https://github.com/AssemblyScript/assemblyscript
I'm looking forward to seeing some benchmarks comparing native binaries with the same program run via wasmer.