Elixir 1.9
If anyone is on the fence on learning Elixir / Phoenix (Elixir's most popular web framework library) please do yourself a favor and give it a shot. If you're on a time crunch and want the best bang for your buck on "why bother learning yet another language to write web apps in?" then watch this talk called "The Soul of Erlang and Elixir": https://www.youtube.com/watch?v=JvBT4XBdoUEI'm not affiliated with the language but I just want to throw out that I've been around since the Geocities era as a web developer and I haven't seen a tech stack or platform this well thought out and so in tune with what makes developing (and testing!) modern web applications an absolute joy. There's really something special here. I see myself sticking with it for 10+ years with 0 regrets.The best part about it is everything is ready today (and was before 1.9 too btw).