Bugzilla
Bugzilla is server software designed to help you manage software development.
News
Release of Bugzilla 4.2rc2, 4.0.4, 3.6.8, and 3.4.14 [ 2012 Jan 31 ] Release of Bugzilla 4.2rc1, 4.0.3, 3.6.7, and 3.4.13 [ 2011 Dec 28 ] Release of Bugzilla 4.1.3, 4.0.2, 3.6.6, and 3.4.12 [ 2011 Aug 04 ]
Features

Bugzilla logo by
Dave Shea
Optimized database structure for increased performance and scalability Excellent security to protect confidentiality Advanced query tool that can remember your searches Integrated email capabilities Editable user profiles and comprehensive email preferences Comprehensive permissions system Proven under fire as Mozilla's bug tracking system
View complete list of features »
Benefits
Improve communication Increase product quality Improve customer satisfaction Ensure accountability Increase productivity Bugzilla can adapt to multiple situations
Bugzilla in Action
http://bugzilla.mozilla.org/
The "original" Bugzilla used by Mozilla projects (including Bugzilla). Note: This is an example of a publicly-available live Bugzilla site, and not a place to try out Bugzilla. Please use Landfill (listed below) if you want to actually try it out. http://landfill.bugzilla.org/
A place where people can play with Bugzilla. http://landfill.bugzilla.org/bugzilla-tip/
See the current development version.
The "original" Bugzilla used by Mozilla projects (including Bugzilla). Note: This is an example of a publicly-available live Bugzilla site, and not a place to try out Bugzilla. Please use Landfill (listed below) if you want to actually try it out. http://landfill.bugzilla.org/
A place where people can play with Bugzilla. http://landfill.bugzilla.org/bugzilla-tip/
See the current development version.