LibrePlan is a collaborative tool to plan, monitor and control projects and has a rich web interface which provides a desktop alike user experience. All the team members can take part in the planning and this makes possible to have a real-time planning.
ProjectLibre – Open source replacement of Microsoft Project.
OpenProject is free and open source software for project management with a wide set of features and plugins and an active community
Agilefant is the most advanced open source web based tool for agile management today, with a rapidly growing user base and a dedicated community behind it.