Application Vault- phpBugTracker

A PHP replacement for bugzilla, focusing on separating the presentation, application, and database layers by using templates and a database abstraction layer. phpBugTracker is deisgned with three goals in mind: simplicity in use and installation, use templates to achieve presentation independence, and use a database abstraction layer to achieve database independence

• Track bugs by multiple users on multiple projects
• Bug history showing changes made to a bug over its lifetime
• Restrict projects to certain groups of users
• The option to store passwords encrypted in the database
• Use of CSS to easily change the color scheme
• HTML templates allow you to completely change the look of the interface
• Flexible bug search capabilities
• Localization -- Have status messages in your native language
• File attachments for bugs
• Anonymous browsing of bugs
• Web-based installation
• Links to a cvs web interface from bug comments
• Bug dependencies

Source: http://phpbt.sourceforge.net/