IBM: Rational Requirements Composer (RRC)

A collaborative requirements definition solution that provides textual and visual techniques to elicit, elaborate, and validate requirements with your stakeholders  

Rational Requirements Composer (RRC) is IBM Rational's requirements context modeling tool. Rational Requirements Composer™, or RRC, allows the analyst and stakeholders to collaboratively create Process/Activity models, Use Case models and definitions, screen mock ups and storyboards. Requirements and Models defined in RRC can be easily conveyed to Rational’s requirements management tools for further modeling and change management.