Help Center Live
Help Center Live is an open-source, community driven live chat & support system. You may easily provide live support on your website just like large companies do with very little work. With Help Center Live, you can provide a real-time, live support or sales person experience.
osTicket is a free and open source ticket system, integrating email inquiries and web-based forms into an easy to use web interface. osTicket is simple, lightweight, and free to use.