What editors besides Emacs have facilities for programming in Lisp?
Vim is lisp-aware. See Larry Clapp’s article at http://cybertiggyr.com/gene/15-vim/. See also http://www.vim.org/scripts/script.php?script_id=221 for the closest thing to SLIME for Vim: VILisp. VILisp basically automates the process of cut-and-paste from Vim into Lisp, and adds a few bells and whistles, but that’s about it. See also the Gardeners project slim-vim, which has linked Vim with an implementation of Common Lisp called ECL, and is working towards integration with SLIME. Eclipse has a Lisp plugin floating around. J has an embedded Common Lisp in it (written in Java).