Aquamacs is a Mac-like version of the powerful Emacs text editor that runs as a standard OS X application. It features extensive customization that enables it to conform better with Apple's standard Human Interface Guidelines (HIG) than standard versions of the editor do. It provides a more Mac-like user experience than Carbon Emacs.
Argh! is an esoteric programming language in the spirit of Befunge, Brainfuck, and friends. It is a nice and simple language with two dimensional code-flow, a combined code/data array, an infinite stack, regular characters for all instructions, no strange braces or symbols, no unnecessary arithmetic operators (add and sub are all you need), and countless other features it doesn't have. The distribution includes interpreters for Argh! and Aargh! (an extended Argh! that is most likely Turing complete), the official specification, editing modes for emacs and vim, and lots of examples.
AutOrg aims to be a text editor, personal organizer, local wiki, secure agenda, and everything in between. For the user interface, it gets its inspiration from text-based minimalism, still providing advanced features for publishing, encrypting, and sharing information. It uses Emacs Org-mode and other extensions, and its main binary distribution runs on a Mac OS X desktop.
The Autotoolset package complements the GNU build system by providing automatic generation of legal notices, automatic generation of GNITS-standard directory trees, a rudimentary portability framework for C++ programs, support for writing portable software that uses both Fortran and C++, additional support for writing software documentation in Texinfo and LaTeX, and a manual introducing both Autotools and the GNU build system in a unified task-oriented manner.
BHL is an Emacs mode which enables you to convert plain text files into HTML, LaTeX, Texinfo, SGML (Linuxdoc), and TXT files. The BHL mode handles three levels of sections, many sectioning styles, common font-styles, any kind of lists, tables, URLs, horizontal rules, and Wiki names. BHL handles a list of links (lol) and a table of contents (toc): you can browse the lol and the toc, insert them where you want, and update the sections' numbers with one keystroke.