Request Tracker (RT) is an industrial-grade trouble ticketing system. It lets a group of people intelligently and efficiently manage requests submitted by a community of users. RT is used by systems administrators, customer support staffs, NOCs, developers, and even marketing departments to track issues, outages, bugs, requests, and all kinds of other things at thousands of sites around the world.
Request tracker is an open source solution for trouble ticketing and problem handling.
How to install and configure this system on linux, unix and freebsd will be published in a post very soon.