Ruby on Rails
"Ruby on Rails is an open-source web framework that is optimized for programmer happiness and sustainable productivity. It allows the developer to write beautiful code by favoring convention over configuration."
Merb
"Merb is an MVC framework that is ORM-agnostic, JavaScript library agnostic, and template language agnostic, preferring plugins that add in support for a particular feature rather than trying to produce a monolithic library with everything in the core. In fact, this is a guiding principle of the project, which has led to third-party support for the ActiveRecord, DataMapper, and Sequel ORMs."
RSpec
"RSpec is a Behavior Driven Development framework for the Ruby language. It provides two frameworks for writing and executing examples of how your Ruby application should behave."
Agile Development
"Agile Software Development is a methodology for software development that promotes development iterations, open collaboration, and adaptability throughout the life-cycle of the project."