Ruby on rails Rails is a full-stack, open-source web framework in Ruby for writing real-world applications with joy and less code than most frameworks spend doing XML sit-ups
OpenWFEru is an open source Ruby workflow and BPM engine
ruby-doc.org, includes: “Help and explanations on why Ruby may be the best choice of programming languages.”
37signals.com produced serious enterprise applications with RoR.
Try Ruby - This site lets you type ruby commands into a little console in the browser window. No installation needed, just a browser. Follow their tutorial! It gives a pretty good, quick run-through of Ruby programming principles.
Why’s (Poignant) Guide to Ruby - Online book that is an easy read.
OnLamp.com RoR Tutorial, with part II
Getting Started With Ruby by Gavin Sinclair
Programming Ruby, The Pragmatic Programmer's Guide by David Thomas and Andrew Hunt
Everyday Scripting with Ruby: for Teams, Testers, and You companion website for the book
JRuby's "complete" JAR for OS X App Bundles – “Now this is really cool. Tony Hursh, commenter on the previous “Advanced Rails Deployment” post, put together an OS X Application Bundle template that allows you to use the JRuby “complete” JAR file as the base of a typical OS X app. What does that mean? That means you just toss the complete JAR into this template, code up some Ruby code, and have a nice dock icon and menu bar like any other app. You can ship the entire app as a bundle, with JRuby as the built-in Ruby interpreter.”
Distributing Rails Applications – “RubyScript2Exe “transforms your Ruby script into a standalone, compressed Windows, Linux or Mac OS X (Darwin) executable. You can look at it as a “compiler”. Not in the sense of a source-code-to-byte-code compiler, but as a “collector”, for it collects all necessary files to run your script on an other machine: the Ruby script, the Ruby interpreter and the Ruby runtime library (stripped down for this script). Anyway, the result is the same: a standalone executable (application.exe).”