Read Lisp, Tweak Emacs by Sacha Chua.
Sacha is writing a series of posts on reading Lisp and tweaking Emacs.
Thus far:
- Read Lisp, Tweak Emacs [Beginner 1/4]: How to try Emacs Lisp
- Read Lisp Tweak Emacs [Beginner 2/4]: How to understand what Emacs Lisp code does
And she is writing content for an email course on Lisp and Emacs, that can be found at:
http://emacslife.com/how-to-read-emacs-lisp.html
Not that Emacs will ever be a mainstream editor for topic maps but it could be useful to experiment with features for a topic map authoring/editing environment.
How to translate useful features into less capable editors will vary from editor to editor. 😉