Project-open
]project-open[ is an Open Source, web-based Project & Service management / ERP system for companies with 3-3000 employees
]po[ helps you to run your business by covering areas including CRM, sales, project planning, project tracking, project collaboration, time sheet management, financial management, invoicing and payments. With more than 1,000,000 lines of code it is one of the largest open-source web applications in the world. It is used by more than 3000 companies in more than 80 countries.
]po[ is a web-based "Enterprise Project Management" software for project-based organizations with 2-200 users. ]po[ integrates areas such as CRM, sales, project planning, project tracking, collaboration, timesheet, invoicing and payments. ]project-open[ is one of the largest open-source based web applications in the world with more than 1,000,000 lines of code. More than 1000 companies in 25 countries use ]po[ to run their businesses.
]po[ is Free, but some of its extensions are commercial.
http://www.project-open.org/documentation/rfe_getting_things_done