Oroville Hospital was the first to use the Scheduling GUI in any capacity. They funded the initial QA of the GUI.
Brian Lord from http://www.sequencemanagers.com/ implemented the GUI in other places and give me some valuable feedback.
EHS did the bulk of the funding and QA on the Scheduling GUI to make it enterprise-ready for VISTA installations. Versions 1.3, 1.4, 1.5, and 1.6 were all funded by EHS. They have contributed some code as well. Thanks especially to Ahmad Al Najar for his excellent QA work and his ideas on how to enhance the GUI. Another special thanks to Tariq Hamkari for his contributions to the code and who helped me navigate EHS politics.
VEN are working on the Scheduling GUI User and Technical Manuals.