* [osTicket](http://osticket.com/) - Open source support ticket system.
* [osTicket](http://osticket.com/) - Simple support ticket system.
* [Otrs](http://www.otrs.com/) - A free and open-source trouble ticket system software package that a company, organization, or other entity can use to assign tickets to incoming queries and track further communications about them.
* [OTRS](http://www.otrs.com/) - Trouble ticket system for assigning tickets to incoming queries and tracking further communications.
* [Request Tracker](http://www.bestpractical.com/rt/) - Ticket-tracking system written in Perl.
* [Request Tracker](http://www.bestpractical.com/rt/) - Ticket-tracking system written in Perl.
* [TheBugGenie](http://www.thebuggenie.com) - Open source ticket system with extremely complete users rights granularity.
* [TheBugGenie](http://www.thebuggenie.com) - Ticket system with extensive user rights system.