Searching FOSS project management software

I have begun the search for a software application to manage project tracking and collaboration. It will need to be browser based so I can have it used internally and externally for Aura Media. Using PHP as the scripting language is the preference as that is what I am most comfortable with, but I am not against a solution that used Python or Ruby. The last requirement is a free and open source license.

In the past I have been a happy Mantis user for bug and issue tracking. So much that I have installed it in a few client sites. However now I want a broader product that includes time tracking and more collaboration features. Also Mantis is showing its age in a visual sense, and this can put off less technical users. Project tracking is the aim, not project planning with features like gannt charts.

In the past I did look at ActiveCollab, but they changed their license, and Streber, but it was immature and moving in a more wiki direction.

My current investigation list is:

Open to any other suggestions.

Software Development, Web

New release of Streber

Streber (a web based project management app) has made its latest release. There is still more work needed before a production release, but so far it looks very good. I have started using it internally for project tracking. Streber was originally to be the next version of netoffice (which I had been using), but all the code has been written from scratch.

Give it a look if you need a web based project management tool.