This part of the GForge collaborative development environment allows fine-grained control over tasklists, bugtracking, and gantt charts, with account management integrated into the overall product. http://gforge.org/
Web-based groupware tool which includes calendar, project-management, time-card management, PDA synchronization, email, voting system and personal to-do list management http://www.phprojekt.com
A tool to schedule and track complex projects. The textual project description is compiled into schedules, status reports and GANTT charts. http://www.taskjuggler.org
Web-based project resource planning system, with project rooms, and tools for managing clients, invoices, time, and cost. Designed for the advertizing, IT consulting, translation and knowledge management sectors. http://www.project-open.com/