Mailman is software to help manage email discussion lists, much like Majordomo
and Smartmail. Unlike most similar products, Mailman gives each mailing list a
web page, and allows users to subscribe, unsubscribe, etc. over the web. Even
the list manager can administer his or her list entirely from the web. Mailman
also integrates most things people want to do with mailing lists, including
archiving, mail-to-news gateways, integrated bounce handling, spam prevention,
email-based admin commands, direct SMTP delivery (with fast bulk mailing),
support for virtual domains, and more. 

Mailman runs on most Un*x-like systems, is compatible with most web servers and
browsers, and most SMTP servers. Mailman requires Python version 1.5 or newer.
Python is a free object-oriented scripting language. A few files are written in
C for security purposes. 

The manual is still only a set of READMEs provided in the Mailman distribution.
For now, more information can be found at www.list.org.