My original intent with More Power to Firmware was to put up some sample Forth code for doing graphics with mouse input in the Open Firmware implementation that Apple uses. I have included a discussion of the Extensible Firmware Interface (EFI), broadening the document’s scope.
Three complete (though prototypical) examples are included: Towers of Hanoi (textual) [...]

A History of Apple’s Operating Systems discusses operating systems that Apple has created in the past, and many that it tried to create, including some technologies that eventually led to Mac OS X. Goals of the document include better understanding the reasons, and wherever possible, the rationale behind Mac OS X and its important components. [...]