osTicket is a widely-used open source support ticket system. It seamlessly integrates inquiries created via email and web-based forms into a simple easy to use multi-user web interface. Easily manage, organize and archive all your support requests and responses in one place while providing your clients with accountability and responsiveness they deserve.
osTicket is an attractive alternative to higher-cost and complex customer support systems; simple, lightweight, reliable, open source, and easy to setup and use. The best part is, it's completely free.

Liberum Help Desk is the complete help desk solution for small to medium sized businesses and organizations. This software provides a simple, easy to use web interface for managing and tracking technical support problems.

Liberum Help Desk is open sourced under the GPL license and free for use. The help desk software is written in HTML and ASP and is easily modified and customized. All that is required to run Liberum Help Desk is Windows Server 2000/XP or later running IIS.

A tailored web-based ICT helpdesk system, with in-built knowledge base capabilities, CMDB functionality and statistical reporting. Fully configurable through the web interface.