I had the good fortune of taking a field trip there in 2018.

The video is a very good overview of the project.

One interesting artifact of "the real world simulates itself" is version control. At Dynamicland, each version of a program is a sheet of paper (with a unique set of fiducials along the edges). If you want to edit a program, you grab a keyboard and point it at the program. A text editor comes up; you make your changes, and hit commit. When you do, it spits out a new piece of paper with your changes. Put it in the view of the camera to use the new version. Take it away and use the old paper to roll the change back.