Does anyone have any knowledge or experience with Gembase?

I’ve been brought onto a project re-writing an old program. It’s an old Gembase application and I am having a lot of difficulty navigating through the DML files, specifically trying to envision how the code is supposed to interact with the UI.

Does anyone have experience with Gembase? I’ve looked everywhere. I can’t even find documentation. I’d be willing to cash app someone a few bucks for their time just to look at a 40ish line snippet of code that could clear a lot of air for me.