From the website,
"This course teaches fundamental processes of software engineering using the highly-productive Agile development method for Software as a Service (SaaS) using Ruby on Rails. This is not a "web programming" course: the emphasis is on learning the processes, tools and concepts, using SaaS as the vehicle. We chose SaaS and Rails because we believe the best tools for teaching these concepts are those in the Rails ecosystem. We will spend the first 2 weeks laying some foundations in terms of the Ruby language and important SaaS architectural concepts, then move into Agile development using Rails."