GPlates: Open-source software for interactive visualisation of plate tectonics

There are screenshots if you just want to browse pretty pics:

https://www.gplates.org/screenshots/

To my surprise, my first click into their web portal section got an error (443, I think) but it opened a few seconds later. I didn't think it would be getting hammered by HN because the vote count isn't that high.

A project from University of Sydney, Australia, so examples I'm looking at seem to skew towards Australia, even one from Scripps Institute, which I understand to be headquartered in San Diego, California.

https://scripps.ucsd.edu/

A certain kind of worldbuilding enthusiast really likes realistic fantasy maps, I wonder if there's any fairly simple way to use this to make them...