mu-cite.el is a powerful citation tool for (X)Emacs.
Homepage: http://www.lab3.kuis.kyoto-u.ac.jp/~tsumura/emacs/mu-cite.html (Japanese) (broken link on 2008-Feb-18)
Download:
ftp://ftp.jpl.org/pub/elisp/mu/mu-cite-8.1.tar.gz
mu-cite 8.1 requires APEL 9.20 or later and [[FLIM?]] 1.12.2 or later.
mu-cite snapshot (14-May-2009) requires APEL 10.7 or later and [[FLIM?]] 1.12.2 or later.
Unpack the archive an type make in the programm directory. Then add the directory to your load-path and write the following in your .emacs file:
(autoload 'mu-cite-original "mu-cite" nil t)
When you use Gnus:
(add-hook 'message-cite-function 'mu-cite-original)
When your use another mailer:
(add-hook 'mail-citation-hook 'mu-cite-original)
By default the citing is very ugly. To fix that put something like this in your configuration file:
(setq mu-cite-top-format '(full-name " write:\n\n"))
(setq mu-cite-prefix-format '(">"))