The most important resources for Ruby programmers.
ruby-lang.orgis the main web site of Ruby. ruby-doc.comholds the docmentaiton of the Ruby programming language and its standard libraries.
Gems are 3rd-party libraries for Ruby. rubygems.orghold the information about them.
www.rubydoc.infoholds documentation of Gems, the 3rd party Ruby libraries.Learning Ruby
learnrubythehardway.organ online book to learn Ruby.
tryrubya web-based editor to try the basics of Ruby.Screencasts
railscasts.comholds lot of screencasts about Ruby on Rails. Many can be watched free of charge. For some you need to pay. The production of new episodes has stopped in Jue 2013.
rubytapas.coma subscription only series of screencasts (2 every week) about programming in Ruby.Web frameworks
Sinatrais a light-weight route-based web framework for Ruby.Ruby on Rails
Ruby on Rails(aka ROR) is the most popular web framework for Ruby.
www.railstutorial.orgis a tutorial for Ruby on Rails.