Newton 2.0 User Interface Guidelines
Apple Computer, 1996. PDF, archive.org
The User Interface Guidelines for the Newton, in our opinion one of the cleanest GUI's ever produced.
Newton Programmer's Guide
Apple Computer, 1996. PDF
Inside Taligent Technology
Cotter, Sean, and Potel, Mike. Addison-Wesley Publishing Company, 1995. Sample Chapters
A detailed look at Taligent, the ill-fated operating system that was a joint venture between Apple and IBM.
OpenDoc Programmer’s Guide
Apple Computer, 1995. StuffIt-compressed PDF
The cross-platform composite document system which unfortunately failed to materialize.
The Xerox "Star": A Retrospective
Johnson, Jeff, et. al. 1989. PDF