Ruby on Rails(RoR) is considered to be one of the favorite languages for web developers. Ruby is a funny programming language that makes the developers happy at work. Some of the big brands like Hulu, Airbnb, Basecamp developed their websites with RoR.
Ruby on Rails Cheat Sheet from DaveChild. A quick reference guide for Ruby on Rails, containing the default directory structure, predefined variables, methods, reserved words and regular expression syntax.