emacs-sieve contains support for editing and managing Sieve scripts in Emacs, using the ManageSieve-protocol. It also contains integration to the popular Emacs news and mail-reader Gnus.
The Insidious Big Brother Database (BBDB) is a contact management utility for use with GNU Emacs and XEmacs. It can hook into Emacs-based mail- and news-readers and automatically collect information on messages therein.
A SQL+CGI addon wrapper for flowtools-ng.
A C library for reading, creating, and modifying zip archives.