SAM is the Horde module permitting to each user to manage his SpamAssassin or Amavisd-new preferences. For example, it can authorize to change SpamAssassin user scores, manage blacklist and whitelist.
User preferences can be stored in a variety of backends such as a SQL database, LDAP storage or on an FTP server.
There is a mailing list available for SAM if you are interested in helping develop SAM or just want to ask questions.
You can download SAM in the Horde CVS Repository (click here to browse SAM CVS tree).