Real World Rails: Caching in Rails
http://www.ibm.com/developerworks/web/library/wa-rails1/

Tate, Bruce
IBM
2007

Abstract:

Ruby on Rails is increasingly showing up as the base framework for sophisticated and scalable applications of medium and large size. Because Ruby is an interpreted language, to bend Rails to your will, you will need to employ many different caching strategies. This article explores the caching strategies that are available to you, including the ones we use for ChangingThePresent.org.