How to: Ticketing systems
*Web-based ticketing system.*

* [Bugzilla](http://www.bugzilla.org/) - General-purpose bugtracker and testing tool originally developed and used by the Mozilla project.
* [Cerb](http://www.cerberusweb.com/) - Group-based e-mail management project.
* [Flyspray](http://flyspray.org) - Web-based bug tracking system written in PHP.
* [MantisBT](http://www.mantisbt.org/) - Web-based bug tracking system.
* [osTicket](http://osticket.com/) - Simple support ticket system.
* [OTRS](http://www.otrs.com/) - Trouble ticket system for assigning tickets to incoming queries and tracking further communications.
* [Redmine](http://www.redmine.org/) - Open source project management/ticketing web application written in Ruby.
* [Request Tracker](http://www.bestpractical.com/rt/) - Ticket-tracking system written in Perl.
* [TheBugGenie](http://www.thebuggenie.com) - Ticket system with extensive user rights system.