HP WinRunner software was an automated functional GUI testing tool that allowed a user to record and play back user interface (UI) interactions as test scripts. As a functional test suite, it worked with HP QuickTest Professional and supported enterprise quality assurance. It captured, verified and replayed user interactions automatically, in order to identify defects and determine whether business processes worked as designed. The software implemented a proprietary Test Script Language (TSL) that allowed customization and parameterization of user input.