Which do you think is the best free and open-source project management software?

As some of you may know, we have featured here a good number of free and open-source project management software (see: project management software, more project management programs) be it desktop or online application. These tools are used to help manage organization or company projects swiftly and systematically.

For our poll today, I gathered 10 of the best free and open-source project management software from our previous lists, and for those who have used some of these applications, please join our poll and cast your votes below.

If you have something to add or share, you may do so via comment.