If you want a structured, high-level intro to several languages, Bruce Tate's "Seven Languages in Seven Weeks" is pretty good. (http://pragprog.com/book/btlang

If you want a structured, high-level intro to several languages, Bruce Tate's "Seven Languages in Seven Weeks" is pretty good. (http://pragprog.com/book/btlang/seven-languages-in-seven-weeks http://pragprog.com/book/btlang/seven-languages-in-seven-wee...) I'd recommend Erlang for its concurrency model (especially comparing how languages like Erlang, Scala, Go and JavaScript/Node handle concurrency and parallelism differently). Haskell is good for functional concepts - understanding FP will help with functional stuff that is migrating into more mainstream languages. Learning a Lisp (Common Lisp or Clojure) is good too. Python is great for the mature community that's developed around scientific projects like machine learning, NLP and such.