RubyGems User Guide
Publisher: RubyGems.org 2010
RubyGems is the premier ruby packaging system. It provides: A standard format for distributing Ruby programs and libraries; An easy to use tool for managing the installation of gem packages; A gem server utility for serving gems from any machine where RubyGems is installed; A standard way of publishing gem packages.
Download or read it online for free here:
by Avdi Grimm - objectsonrails.com
The book is documenting some guidelines and ideas for applying classic object-oriented thought to Ruby on Rails applications. It is aimed at the working Rails developer who is looking to grow and evolve Rails projects while keeping them flexible.
by Mitch Guthrie - bigfatrails.com
A book designed around teaching Ruby on Rails in a precept upon precept fashion. Both theory and practice driving your knowledge. If you are a beginner, the purpose of this book is to simply get you there in small, manageable steps.
by Chris Pine - Pragmatic Bookshelf
Pine teaches you how to program in Ruby with a minimum of fuss or bother. Starting with simple one-line programs, you'll see how to have your webpage send you email, to shuffle your music, to rename your photos from your digital camera, and more.
by Mark Slagell
Ruby is an easy object oriented language: it is designed to be easily read and written. This User's Guide will get you started at invoking and using ruby, and give you insights into ruby's nature that you may not get from the reference manual.