Started with http://rubykoans.com/
Ruby is a language of careful balance.
Its creator, Yukihiro “Matz” Matsumoto, blended parts of his favorite languages (Perl, Smalltalk, Eiffel, Ada, and Lisp) to form a new language that balanced functional programming with imperative programming.
He has often said that he is “trying to make Ruby natural, not simple,” in a way that mirrors life.