Open source project management tool - PHP

Hi guys I would like to know what open source project management tools you use for your projects. We are looking at installing one that is PHP based and is easy to use. We have found: http://www.projectpier.org/ and http://trac.edgewall.org/ Has anyone used the above and how did you find them? Also are there any others you would recommend or not recommend and why? Thanks in advance. Regards Angelo http://www.wapit.co.za http://www.elemental.co.za