josevalim/elixir is a programming language for the Erlang environment and its virtual machine, which integrates into the Erlang environment and has a similar focus as Erlang. However, Elixir provides a Ruby-like syntax and some interesting extensions as well as, of course, interoperability with Erlang code (otherwise it wouldn't make sense, because Erlang is not just the rather strange language, but above all the server structure and the libraries).