[jzwinck]

This might be more accurately titled "The Craft of Making Text Editors." It is mostly not about Emacs, rather about more abstract ideas around user interface (see the quaint Joystick section) and text editing:

> This model is the basic two-dimensional form. Instead of editing a line, the user is editing in a quarter-plane, with the origin usually in the upper-left corner. Conceptually, the user can move freely in the two-dimensional quadrant. In practice, the editor usually only stores the non-blank portions, as storing an infinite-quadrant's worth of data can be prohibitively expensive. Some systems may impose fixed upper bounds on the width or length of the quadrant.

Sure, that's fine I guess, but this doesn't help me understand how to use or program Emacs. And most of the code is in C, not Elisp.

[ScottBurson]

As I recall, most of the work Craig did on this book was from the early-to-mid 1980s, before GNU Emacs (or at least before it became popular). In fact, I believe it grew out of his B.S. thesis, written in 1980.

Anyway, not every programmable editor is programmed in Elisp.