Adapters for Rational TestManager
Ring-Zero Sofware provides Test Input Adapters, which provide traceability between non-Rational requirements tools and TestManager test cases and test plans and Test Execution Adapters, which allow non-Rational functional testing tools to be driven by TestManager>> more

Catalyze Suite from Steeltrace provides a pragmatic approach for organisations to capture, document and model Business and System Requirements. Steeltrace claims Catalyze yields a 40% per project ROI involving minimal deployment time

DOORS
Telelogic DOORS®, the world's leading requirements management tool, is a multi-platform, enterprise-wide system designed to capture, link, trace, analyze and manage changes to information to ensure a project's compliance to specified requirements and standards >> more

Fitnesse
FitNesse is a collaborative testing and documentation tool which provides creation of documents, specify tests and run those tests. FitNesse runs within a web server and requires no configuration or setup (open source) >> more