An open source help desk and support ticket system for WordPress using jQuery. Easy to use for both users & admins.
Updated frequently, and that's excellent. Had to modify it for some special fields I needed, and more or less, this was fairly easy to customize.
A big, BIG, minus is that they have changed the naming convention of functions and variables several times along the way. I can now spot four different names for these: wpsc_, wpscst_, wpsct_, wpst_ (you can spot all four on submit-ticket.php on the first 70 lines of code). I have absolutely no idea, which ones are typos and which are correct - and I actually think they themselves don't know anymore. The code is a big mess and most of the bugs are related to this. This makes the manual update extremely time consuming. (On the plus-side they do fix these fairly quick whenever one is found - and if you haven't modified the code, update as frequently as you can)
All in all - does what it's supposed to - new functionalities added often enough.
If you are looking for a basic text email exchange program that you can use for logged in users only (and get rid of all other spammy emails), then this is an easy solution.
* Can not attach files
* Users can link text when creating emails but admin cannot use linking.
I need help, plugin not working in internet explorer