In case someone missed this one (or I missed the note about someone not missing this one): http://www.ercb.com/ddj/2001/ddj.0102.html They wrote: Overall, I give this book full marks, and I think that it deserves to become the standard reference for Ruby programmers. They didn't realize it is already the standard reference right after source code :). Or that there's a tool like ri. (Well, to be precise there wasn't any when they wrote the review... :) - Aleksi