Crafty Syntax Live Help (CSLH) is an open source live support solution

Help Center Live is a Live Support tool written in PHP

Hesk is Free PHP Help Desk Software that runs with a MySQL database

osTicket is a widely-used open source support ticket system

ExoPHPDesk is a free php helpdesk software

phpSupport is your customer friendly trouble ticket system

Web Messenger is an open-source live support application written in PHP and MySQL

phpOnline is a live customer support system

phpMyFAQ is an open source FAQ system using PHP

iQDesk is a unique software specifically designed for freelancers, small and any type of one-person-business

PHP Support Tickets is a powerful, all-in-one email helpdesk / ticketing software that is incredibly easy to use