UniPress "Evil Software Hoarder [TM]" Emacs had a vi emulation mode such that when you typed ":q", it flipped you over into an Emacs shell window with key bindings to behave just like you'd expect had you actually exited your text editor. Of course the shell mode was hacked so "vi foo.c" would flip you back into a vi-mode buffer on foo.c. Poor innocent vi users didn't even realize they hadn't left the editor! It was kind of like being in the Ematrix.