What are its promising uses outside of web development? From the little I've seen it looks like a beautiful functional programming language, but I'm not even tangentially involved in web development.
My current favorite things in Elixir are not particularly web-related:
- Nerves, embedded Linux + the BEAM VM to do IoT-style things in a nicer way. The workflow compared to something like working from Raspbian seems a lot more sane to me.
- Scenic, OpenGL-rendered UI, for embedded hardware or other purposes. I recently used it to get text-rendering and geometries onto an eInk display with Nerves. One big reason for the creation of Scenic was to give IoT/connected devices UI that doesn't require a web stack. For many reasons, with security definitely being high on the list.
The erlang Vm’s roots go back to telephony switches, so there are many cases beyond web.