Functional languages have begun to gain popularity and coverage as well.
On the frontend Elm is excellent. On the backend Elixir and the web framework Phoenix offer top notch developer experiences.
If you have experience in the dot net world... Dot Net Core is shaping up to be a revolutionary rewrite of the dot net ecosystem. It's fast and lean, as well as cross-platform.
If you are into lower level languages, Rust & Go have picked up a ton of steam in the past few years. Until recently they have been stuck in the systems level programming niche, but Go especially is beginning to take hold for API and more "front side of the backend" development.