Code
ox-leanpub
Ox-leanpub is a Leanpub book exporter for Org mode. It allows you to write your material entirely in Org mode, and manages the production of the files and directories needed for Leanpub to render your book. I use this package to publish my books.
For a comprehensive introduction to publishing with Org mode and Leanpub, check out my book Publishing with Emacs, Org-mode and Leanpub!
Code
GrabCartoons
GrabCartoons is a comic-summarizing utility. It is modular, and it is very easy to write modules for new comics. It’s one of my oldest open-source projects, and still in use!