There is a new project in town called freelancerKit.

I've tinkered with the demo and seems practical and easy to use. There have been a lot of Project Management programs put together, recently the ever popular BaseCamp HQ and Active Collab.

I suppose the difference with this one is the simplicity, and affordable one time price. It's targeted more at freelancers but seems to work with a company as it offers Employee user permissions as well.

The short description of freelancerKit is that it is a PHP Project Management, PHP Groupware, PHP Collaboration, Note taking and File Management.

Check it out here.
And the demo here.