OTRS is an Open source Ticket Request System (also well known as trouble ticket system) with many features to manage customer telephone calls and e-mails. The system is built to allow your support, sales, pre-sales, billing, internal IT, helpdesk, etc. department to react quickly to inbound inquiries.

Bugzilla is one example of a class of programs called "Defect Tracking Systems", or, more commonly, "Bug-Tracking Systems". Defect Tracking Systems allow individual or groups of developers to keep track of outstanding bugs in their product effectively. It can easily be used as a full help desk system.

Bugzilla has matured immensely, and now boasts many advanced features. These include:

- integrated, product-based granular security schema
- inter-bug dependencies and dependency graphing
- advanced reporting capabilities
- a robust, stable RDBMS back-end

RT is an enterprise-grade ticketing system which enables a group of people to intelligently and efficiently manage tasks, issues, and requests submitted by a community of users. It is widelyt used used as an helpdesk system.

The RT platform has been under development since 1996, and is used by systems administrators, customer support staffs, IT managers, developers and marketing departments at thousands of sites around the world.