PHP based Project Management Software?

Greetings,

I checked the net but am not able to find any good PHP / MySQL based Project Management Software.

Requirements would be:
a) Open Source so that we could modify the code.
b) Paid or Freeware are ok as long as we could customize the code and no encrypted code is there
c) Can be hosted on the intranet / web without any additional licensing and user blocks (for example we could have 10 employees or 100 employees) so it should not be a per user costing for the Project Management Software.

Should have following features
a) General User Management, employee management, adding their salary and monthly hours of work and allocating projects to each employee.
b) Project Management
c) Cost Management
d) Project Completion and Billing
e) Hourly user chart (how much each allotted employee took on the project)
f) Billing per employee and adding profit (for example if any employee is paid $5000 a month for 8 hours X 20 days - 160 hours) so billing per hour comes to 31$ then it shows the cost per employee. Then the admin could add say 30% profit to it and hence if that employee spends 10 hours on the project the bill 41 X 10 = 410$.
g) Admin could set the users on the project and then each user could check his/her tasks and add their hours / feedback to it.

Thanks in advance for all the help. Highly appreciated.

Find things you like on this page: http://www.webdesignerdepot.com/2009/02/14-applications-for-project-management-and-collaboration/ and/or http://www.cmscritic.com/resource-lists/cms-list/
then check its details on this page: http://en.wikipedia.org/wiki/List_of_content_management_systems

I was going to suggest Moogle, but its a teaching CMS, sorry can’t remember what I used years ago… but my first stop is generally that Wiki page when looking for something specific

thank you @looped for your response. But most of the links are for CMS Software. I was more interested in Online Project Management Software so if you have any links that would be great.