" Over the past decade Stallman created a powerful editing program called Gnu-Emacs. But Gnu’s much more than just a text editor. It’s easy to customize to your personal preferences. It’s a foundation upon which other programs can be built. It even has its own mail facility built in. Naturally, our physicists demanded Gnu; with an eye to selling more computing cycles, we installed it happily. "

― , The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage