[New] Free Help Desk Software, Customer Service Management (CSM) and Support Ticket Applications (PHP Versions)

Help desk software allow you to create a customer support ticket system on your site. Such tickets let you track customer support requests
(or if you are a software firm, track bugs) and follow up on them. Some of the software provide both an email interface in addition to a web-based interface, allowing you to create and follow up on tickets using whichever method
you prefer. As always, the software listed here are free. (In fact, most, if not all, are also open source.)

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