Our team has been using FreeScout for the past month or so and it has been great! We came from no helpdesk solution since we have a Free/Open Source requirement for our project stack.

One aspect of Freescout which we appreciate very much coming from a very top heavy and overbuilt system is how light Freescout is on server and browser resources. Freescout is the only open source helpdesk written in PHP and simple enough to administer for a small business. The other open source solutions are either hideous and ugly or so overwrought that installing and maintaining a working install would almost require hiring another server admin with specialised knowledge.