- Created by David Heinemeier Hansson while working on Basecamp in 2004.
- David was hired to build it and happened to be a Ruby fan at the time.
- Included with Mac Os X in 2007.
- Uses Model-View-Controller and scaffolding ('wizards').
- Uses ActiveRecord to autmatically map SQL tables to data structures.
- Uses Prototype and scri.ptaculo.us.