REQADM is an open source helpdesk ticket tracking system. It started out as an internal tool created by a system support group, and has evolved to meet their needs as they grew to support a user base which grew from a few hundred to a few thousand users.
The author presented a paper at LISA '99 describing the system and the lessons learned about structuring a help desk facility, as well as about the toolset itself. You can read this paper here (see below).
After that presentation, a number of other users at various commercial and educational sites have picked up REQADM and begun using it to run their helpdesk systems.
We are in the process of setting up this SourceForge site to better facilitate communication between them about REQADM, as well as providing the source code to REQADM itself in a better way.
This is a full-fledged request tracking system, consisting of approximately 45,000 lines of C++ code, supported by a number of Perl scripts.
It allows customers to submit tickets by free-form E-mail, web forms, command-line utilities, C++ API-based clients, and native GUI tools on UNIX (X) and Windows platforms.
Administrators may use the above interfaces to periodically update tickets through the worlflow leading up to resolution. Updates are sent to the submitter, owner and other interested parties. Any e-mail replies are automatically tracked in the ticket history, allowing the support tech and customer to simply correspond via e-mail as they discuss the issue.
A comprehensive high-level report generation tool is provided, which can be run in batch mode (such as a cron schedule) to publish charts and graphs of your helpdesk statistics.