There's no doubt about it: Mercury Interactive (now part of HP) tools such as WinRunner, QuickTest Professional, and LoadRunner are some of the most popular tools for automated software testing. However, for the remainder of the development lifecycle, many organizations have adopted IBM Rational tools such as ClearCase and ClearQuest for software configuration management, RequisitePro for requirements, Rational Software Architect (RSA) for modeling, and the list goes on. In short, companies today are typically using Mercury tools for testing and everything else from IBM Rational.
Testing and the other components of the development process are bridged by a test management tool, and again both vendors have product offerings which fill this need: Mercury makes two popular tools for test management, TestDirector (legacy product) and QualityCenter, while IBM Rational makes Test Manager (legacy product) and it's newly-released ClearQuest Test Manager (CQTM), which is a test management tool based on ClearQuest, its widely-adopted, highly-customizable, and enterprise-validated tool for change management.
As organizations seek for the "holy grail" of software development, an end-to-end integrated toolset comprised of the tools their users' prefer to use and the ones which work (or work best) in their development and deployment environments, they are often presented with a tough decision -- bridging testing with the rest of the development process means choosing between the two vendors' test management tools.
Each tool carries its own list of pro's and con's. However, software integration vendor 
Ring-Zero Software has simplified this choice by giving software development organizations more options and flexibility in making this decision. Two of Ring-Zero's most recent integrations are Test Adapter for WinRunner and Test Adapter for QuickTest Pro, add-ons for IBM Rational ClearQuest Test Manager (CQTM), Rational Application Developer, and Rational Functional Tester which bridges IBM Rational software tools and processes with Mercury Interactive WinRunner. These integrations are particularly attractive to organizations who would like to avoid the cost and complexities of using Mercury TestDirector and QualityCenter, with its synchronization-based integrations with IBM Rational tools, whilt at the same time leveraging the popular ClearQuest tool for Test Management. The integrations are also interesting to testing departments which use mixed vendor toolsets due to the simple fact that some tools work better than others under certain environments or against particular applications under test. Also, for testers transitioning from Mercury to Rational functional testing tools, these integrations can be lifesavers. Testers are often encouraged to create new tests using Rational tools, but testers still need to maintain the ability to leverage past work and maintain the ability to execute Mercury tests.
Perhaps most important, these integrations are commercial and supported by a company with business relationships with most of the primary tool vendors and a track record of supporting its products across hundreds of global Fortune-100/500 companies. Mercury's test management tools do not have official support for driving IBM Rational testing tools. What's more, Mercury often claims to offer integrations which allow execution of tests via IBM Rational tools, yet a simple Google search paints a different picture. One might conclude that these integrations either (a) don't exist, or (b) are "dirty little secrets" which are not officially maintaned or supported. How many organizations are willing to bet the enterprise on vaporware or hacks?
ClearQuest Test Manager is our preferred choice for test management for many reasons. IBM Rational has kept its interfaces open and enlisted the help of experienced ISV's to build commercial, supported integrations with competitors' tools. CIO's and CTO's are happy - organizations are able to further leverage the familiar change management tool which has already been widely validated in the enterprise. CFO's are happy because choosing ClearQuest means saving potentially hundreds of thousands, or millions, of dollars: CQTM is available for free with ClearQuest 7.0. Testers are happy because they are free, thanks to the Mercury integrations developed by Ring-Zero Software, to use Rational, Mercury, or both vendors' testing tools. CQTM's open interfaces guarantees that organizations are not left stranded without options if they decide to augment or replace their testing tools in the future.
