Modes by Alex Schoeder
The greatest editor of all times.
http://www.geocities.com/kensanata/emacs.html

386SWAT
A Protected Mode Debugger which provides debugging services to real mode, protected mode, virtual 8086 mode programs, DPMI and VCPI clients, and Win 3.1x and Win95/98 programs under any memory manager while occupying only a few kilobytes of low DOS memory.
http://www.sudleyplace.com/swat/

HTML Helper Mode
Major mode for editing HTML files. The current address of the mode originally written by Nelson Minar and now maintained by Gian Uberto Lauri.
http://www.nongnu.org/baol-hth/

Inform Mode
A major mode to edit programs written in the Inform programming language. Supports the usual program mode functions: automatic indentation, moving over expressions, comment and string filling, font locking, tags-file support, starting compiles and parsing errors.
http://www.rupert-lane.org/inform-mode/

Emacs Rexx Mode
The current version of the Rexx mode for Emacs with complete font-locking and a Rexx-debug minor mode.
http://www.sve.man.ac.uk/General/Staff/perrin/rexx.html

CC Mode
The development homepage of the Mode for editing C/C++ and other languages with similar syntax.
http://cc-mode.sourceforge.net/

PHP Mode
The world's largest development and download repository of Open Source code and applications
http://sourceforge.net/projects/php-mode/

Science and Spirituality
Two modes of cognition are described: a rational-scientific mode and an intuitive-spiritual mode.
http://cogprints.org/2680/01/spiritualitysystems.html

Haskell Mode for Vim
Syntax highlighting mode for Vim, by John Williams.
http://www.haskell.org/libraries/hs.vim

PSGML Mode
PSGML is a GNU Emacs Major Mode for editing SGML coded documents.
http://www.lysator.liu.se/projects/about_psgml.html