Ticket tracking and customer management solutions?

An anonymous reader writes: Like many Slashdot readers, I'm sure, I run a small side business doing IT consulting in addition to my day job. I'm looking for a good open-source ticket tracking system that I can run under Linux, preferably one that also has some customer management features. I'd like to be able to maintain a separate record for each job, along with time tracking, work logs, and information about the customer. Much of what I see on Sourceforge is, as usual, pre-pre-pre-alpha with no actual code. Does anyone have any suggestions for a project that might fit my needs?