Visure - Visure offers  a flexible , modern and complete requirements ALM Platform (Application Lifecycle Management).

Jama - Jama combines requirement management software with enterprise collaboration capabilities to solve product delivery problems.

Reqtify - Reqtify is an easy to use, interactive application for managing requirements.  

Valispace - Valispace is a modern browser based tool for complex hardware development that connects data for engineers, efficiently manages requirements and much more.

Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.

Helix ALM - Helix ALM is the single, integrated application that lets you centralize and manage requirements, test cases, issues, and other development artifacts and their relationships.