Freedcamp is free for an unlimited number of users and projects.Users are provided a number of basic applications on initial sign-up and can add additional applications later on. The core applications allow users to assign tasks to people, set milestones, schedule events on a calendar, use discussion boards, and track time spent on tasks.
Freedcamp's free apps include:
Tasks - Shared task lists with subtasks
Team Collaboration - Invite team members, chat/communicate and share the workload