Another comment much further down the page says:
"Believe it or not, from a cursory reading of that MPW Pascal code on the left hand side is taking an input buffer, and stripping the whitespace from it, and putting the result into another buffer.
That's a lot of code to accomplish not very much.
From the title bar, it's a Hypercard extension."
The code in the right-hand window seems to be a script for checking out files from a version control system.