I don't know if any source is still available, but for a long time I've been
fascinated by Ivan Sutherland's Sketchpad running on the TX-2:
https://www.youtube.com/watch?v=USyoT_Ha_bA
Since Sutherland's technical report is also on the web
(
https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.html) I reckon it would make for
a great 3rd-year Computer Science graphics assignment, to replicate Sketchpad using a high
level language. A look through the report shows the
use of rings, linked lists, recursion, storage considerations, maths, graphics and so on
(only needing to replace the light pen with the mouse
of course) which could be a fascinating exercise for a student.
Yes there are already Sketchpad-named apps and Sketchpad-like programs, but I'm not
sure if there is a near-100% faithful recreation of that
original program as demoed in the film out there.
Steve.