Quack is a package for Emacs by neil-van-dyke that enhances Emacs support for Scheme. It is layered atop the standard packages cmuscheme.el, by Olin Shivers, and scheme.el, by Bill Rozas and Dave Love.
Quack is available online at http://www.neilvandyke.org/quack/, though some GNU/Linux distributions include it as well.
apt-get install emacs-goodies-el
As of March 2, 2009, quack is set to be included in emacs-goodies-el in Debian. quack-el, the previous package, was removed from the archive in January of 2008. All of the autoloads do not work perfectly, so you should still add (require 'quack) to your ~/.emacs.
Please add other distributions.
cd /usr/share/emacs/site-lisp wget http://www.neilvandyke.org/quack/quack.el echo "(require 'quack)" >> ~/.emacs