I was looking for an off-the-shelf solution to a user-based work tracking system, and having tried out project management, time tracking & other extensions, I decided that a helpdesk might best fit my needs. From there, it was a matter of finding the best and best-supported extension, and the MaQma Helpdesk rose far above the rest.
The developer responded immediately to my inquiries, assisted my integration, and included some of my needs in subsequent updates to the system. The Helpdesk itself is robust, solid, and straight-forward. This extension gets the highest rating.