Speaking of user interface guidelines, developer Matt Sephton and others compiled many of Apple’s human interface guidelines, starting from 1980, all the way to 2014, including some goodies like early drafts, NeXT, Newton, and so on.

Elsewhere, designer Geof Crowl put together his own list that goes broad instead of deep, including style guides other than Apple’s, too.

The list was made in 2020 and a few links are already broken, but there are some gems here like the modern Designing for Playdate, or the classic Zen of Palm from 2003. You can learn a lot just by grabbing one and scanning it.

Let me add a few more I know of:

• Amiga User Interface Style Guide (1991)
• Magic Cap Concepts (1995) with a strange subtitle “Everything right is wrong again”
• Java Look and Feel Design Guidelines (1999)
• Windows Interface Guidelines for Software Design (1995)