One can argue that Basecamp, like other hosted solutions, provides superior feature depth and that Microsoft Project is much more powerful - but, these programs all lack that mainline connection to your website, can cost a lot of money, and limit accessibility to your own information.
Project Fork is about building upon your existing Joomla infrastructure, including it's user-base and developing a collaborative solution which allows Project Tracking accompanied by dedicated Task Lists, Versioned File Storage with comments (Pro version), Messaging (like a forum) and Task-based Time Tracking.
As with any tool, one should always examine their requirements first and *then* determine if the tool suffices. Project Fork absolutely delivers on it's promises.
It's a free component, but I highly encourage throwing some monetary support at these guys - they deserve it!