LiteRM is a comprehensive, but light-weight requirements manager.
LiteRM stores various types of requirements and supplementary information e.g., user roles, acceptance test designs, and definitions. It provides tailorable templates for each information type along with support for states (e.g., unimplemented) and links (e.g., use cases to test designs).
LiteRM costs $19.95 (+ $21 for WhizFolders using this link)
Manage quality goals early to avoid iterative icebergs