Obviously I have to post this.
Knuth’s Tex for the Math-kings of sigma, and pi,
Unix vim for the Server-lords with their O’Reilly tomes,
Word for Mortal Men doomed to die,
Emacs from the Bearded One on his Gnu throne,
In the land of Stallman where free software lies.
One Emacs to rule them all. One Emacs to find them,
One Emacs to take commands and to the keystrokes bind them,
In the land of Stallman, where free software lies.
— Raffael Cavallaro, gnu.emacs.help
In a similar literary vein: Emacs Haiku. To laugh with these is to weep for what you have become.