A Free Course on Sinatra
To celebrate the release of Sinatra 1.0 RubyLearning announces the first-ever, free online “Introduction to Sinatra” course starting from 15th May 2010.
Sinatra – quickly create tiny web apps and services

What’s Sinatra?
Sinatra is a micro-framework for quickly creating tiny web-applications and small services in Ruby. It is not a Model-View-Controller (MVC) based framework.