>
> I'm just starting with Maxima. What is the best way to learn about how
> to add features to Maxima?
Did you have any particular features in mind? It may make a difference.
For many applications, the simplest way is to just write programs in the
Maxima language, so I guess you should learn that, first.
If, for some reason, that is not sufficient, you should learn Common Lisp
and read some of the implementation documentation.
And ask.