> Some code associated with Nedryland is visible on screen. It looks like actual source code[9] with Classic Mac OS API functions calls

The source code shown is example code included with the Macintosh Programmers Workshop, Apple's original IDE for the Mac. Originally sold as a separate product, eventually it was provided on the Developer CDs and then as a free online download as serious developers had moved to CodeWarrior. https://en.wikipedia.org/wiki/Macintosh_Programmer's_Worksho...

One of the windows shows the example for how to make a HyperCard XCMD and the other one looks like an MPW script for using Apple's Projector source control.

edit: Found the files in question in a copy of MPW 3.1. Line endings have been converted from CR to LF and the character set from MacOS Roman to UTF-8 to display easily in modern browsers

MPW 3.1:Examples:HyperXExamples:Reduce.p https://kalleboo.com/linked/Reduce.p.txt

MPW 3.1:Examples:Examples:CheckOutActive https://kalleboo.com/linked/CheckOutActive.txt

MPW 3.1:Examples:Examples:DerezPict https://kalleboo.com/linked/DerezPict.txt