I am sure others are going say, or have said, something similar: If you had to learn a second language, the question has many great candidates for answers. Pyt

I am sure others are going say, or have said, something similar: If you had to learn a second language, the question has many great candidates for answers. Python, Ruby, Scala, or a more functional language. Maybe a rapid prototyping language. If you believe in mobile first, then Swift, or Objective-C, or Java. If you need to manipulate data then Python, R or Julia. If you believe that you should learn the "foundations" first (read: legacy language) you could go back to C. If you like the Microsoft ecosystem, C#. If you work with Excel (what a beautiful product) then VBA and so forth. But if you want the first language, then I think the answer is simple: Javascript. I think it is an ugly language, and I wish another language had become to dominant, but history is what it is. Its in the browser, and so it is everywhere. You have to work with it for the most interfaces anyway. A little sooner, and I am sure this would start a mini flame war, but as it is, this comment is safely tucked down the chain.