With the current company and projects Im working on we have been using Mantis bug tracker since i set it up about 2 years ago. At the time of its introduction it was a big change for the team who weren’t used to using proper [Basic required] developer tools to get the job done.

Here are some of the great things we have found in using Mantis:

• Completely web based
• Runs on LAMP(cheap servers/hosting, and we have in-house experience in managing these)
• Configuration notifications via email on changes to tasks. We currently use this to notify the assigned user and the reporter of a task when changes are made to their task.
• Almost simple enough to use without any training for our users.
• Granular permsions for users and groups, [Can also be a pain with lots of projects and cross user dependencies if not set up right]

Some negatives

• No summary emails listing the issues still open that need to be followed up.
• Searching is not very good, and can lead to duplicate bugs been created.
• Permission model can get very combersum with a lot of nested projects

Overall a very good free product.