Learn or reference Ruby with example code and challenges.
This module assumes you have some programming knowledge already and want a quick guide/reference to Ruby code. For an easier version of this tutorial, see Learn Ruby for Beginners.
Most of the example code is taken from LearnXinYminutes (by davefp and others) and is licensed under the Creative Commons Attribution-ShareAlike 3.0 License. See learnXinYminutes.com.