[hanche]

> PDF is a subset of Postscript

That’s a bit of an oversimplification. There’s a whole layer of structure atop the postscript subset. Much software deals only with that layer, never looking into the chunks of rendering code. That’s plenty complicated already!

> Postscript (and PDF) are also postfix, which can be confusing.

I handwrote quite a bit of postscript wsy back when. It wasn’t that bad, really, you just had to keep the state of the stack firmly in your head. Being used to HP scientific calculators helped. I would never dream of handwriting a pdf file, though. Even the low level parts are harder to deal with, since most command names have been shortened to a single letter for efficiency.