> Everything in the set was real. We couldn't fake any of it, because audiences are so sophisticated now in their knowledge of computers. > ... > - Cory Faucher (Special Effects Coordinator)
This sentiment seems to run throughout the movie, and I believe it's why it's held up so well in terms of visuals, I don't think it would have aged nearly as well as it has if more CGI (or other ways of "faking" things) had been been used.
As for the question (in <references[9]>):
> Some code associated with Nedryland is visible on screen. It looks like actual source code[9] with Classic Mac OS API functions calls.
That looks like old Pascal, and since the window has MPW (Macintosh Programmers Workshop) in the title, that's probably it?
It's funny they say this back in 1993. It feels like we've gone from computers being a niche but beloved piece of tech to a ubiquitous and reviled piece of tech.