mantis -- A web-based bugtracking system
http://mantisbt.sourceforge.net/
Mantis is a web-based bugtracking system. It is in active development
and is considered beta.
It is written in the PHP scripting language and requires the MySQL
database and a webserver. Mantis has been installed on Windows, MacOS,
OS/2, and a variety of Unix operating systems. Any web browser should
be able to function as a client. It is released under the terms of the
GNU General Public License (GPL).