GNU GNATS is a set of tools for tracking bugs reported by users to a
central site.  It allows problem report management and communication
with users through various means, including e-mail, Web and a network
daemon.  GNATS stores all the information about problem reports in its
databases, consisting of plain text files and it provides tools for
querying, editing and maintaining these databases.

WWW: http://www.gnu.org/software/gnats/