Obligatory link to my list of alternative BEAM languages.
https://gist.github.com/macintux/6349828#alternative-languag...
https://gist.github.com/macintux/6349828#alternative-languag...
For Rust there is:
https://docs.rs/actix/0.10.0/actix/
and Lunatic (which compiles to WebAssembly): https://news.ycombinator.com/item?id=25160474
(edit: added Actix and Lunatic, formatting)