Clojure
Clojure is a dialect of Lisp with a focus on functional programming. It was released in 2007 by Rich Hickey, and has since gained a lot of popularity among web developers.
To learn about some of the language's core functions, you can consult the documentation.
You could also consult any of these articles:
- Summary - Why use Clojure?
- Basics - Defining some variables and functions.
- Conditionals - Using logic to add complex control flow to your programs.
- Let Bindings - Using local variables.
- Loop and Recur - Using recursion to create loops in Clojure.