...Software developers and quality assurance engineers may use this architecture to create new toolchains, new workflows based on the toolchains, and plug in a variety of measurement tools to conduct GUI testing.
More detail is presented in this publication:
GUITAR: An Innovative Tool for Automated Testing of GUI-driven Software. Bao N. Nguyen, Bryan Robbins, Ishan Banerjee, and Atif Memon. Automated Software Engineering Journal. p.21, 1. 2014