As of 2009-12-06, this project may now be found at http://code.google.com/p/etraxis/.
Free web-based bug tracking system written on PHP. Some of the main features are: fully custom templates, advanced filters, LDAP support, email notifications, subscriptions, reminders, flexible permissions management, graphical project metrics, etc.
Awsome tool with great capabilites! We've deployed it for one of the teams within Motorola Inc. Mobile Devices Software division. It was used for communication between management, test and CM integration teams. Several dozens of users submitting and processing dozens of records each day and no problems at all. Thumbs up!