Downloading HercGUI 1.12.6 from our website was free. The software is included in Office Tools. The actual developer of the program is Software Development Laboratories.
From the developer:
HercGUI is a standard Windows program that makes using the Hercules emulator much easier to use. It allows you to change configuration settings and add new devices by means of simple and easy to understand Windows dialogs just like any other Windows program you are already familiar with using.
You may want to check out more software, such as NBS LawTrak, which might be related to HercGUI.