I have been planning to start such a series where I will focus on some promising projects which are developed in PHP. Many of us don’t even know that such projects exists and are totally lost when they need one. This series will help you to get familiar with such open source projects.
If you are looking for a nice help desk package, don’t want to spend dimes for it but taste the flavour of professionalism – trellis desk may help you. I have recently came by their site and surprised see the intuitive UI and user friendly system. It has a built in knowledge base, skin manager and email piping beside general help desk features. It is written in PHP5 with support for MySQL as backend database server.