A company selling tools that facilitate the software design process. From requirements and design through to testing and release, this company has a piece of software to sell you. Albeit a Very expensive one.
Rational are also infamous for their overly protective and user-unfriendly attitude to software licensing. To use one of their products, you must install a license manager on your machine, enter in a startup license key, request a permanent license key from the license manager, mail the request off to Rational Software, receive the email, run the attachment. This causes problems if you want to move the application to another machine or your hard drive crashes. If you do need to get at a license that has been lost, you just email rational, tell them the machine that the license was on and they change their license server so that you can request a new one.
Products by Rational Software (incomplete):
- Requisite Pro. A Microsoft Word based software requirements capture tool and database.
- Rose. An unfriendly UML software design tool.
- ClearCase. A Unified Change Management (UCM) tool. Very expensive, but could save you time if you are releasing multiple versions of software concurrently.
- ClearQuest. A defect and Change request database closely tied to ClearCase.
- TeamTest. An automated test tool. Good for apps that use standard windows controls, but a pain if you are using custom UI components.
Rational subscribe to the Microsoft school of "integrating" applications. If you buy one application, you can be sure that it will run far better if you buy the complimentary Rational apps. | 
