What to study for general development in programming (new language, framework, theoretical foundations)?

Question

IT education

Good afternoon.
I want to start learning something new in programming, for general development and not to get stuck in the current condition. What are the possible directions: a new language, new technologies, theoretical foundations (algorithms, etc.).
What I know: Ruby on Rails (main activity), JavaScript (as a front for ROR), C++ (Qt) studied for myself (basic foundations, made simple applications), Perl (basics).
What can you recommend, so that in addition to general development, a prof. activity, may become a trend in the future, or just a terribly handy thing (I really like Ruby in terms of convenience and conciseness).
Thank you.

Answer 1

Go (golang)

Answer 2

Scala . Interesting, multi-paradigm and in demand.