It depends on what you are really trying to do. If you want to do timelines and Gantt charts for management views, planner is probably good, but if you want more low-level, direct access to something like software coding you'd want to glue together a version control system and bug/feature tracker combination like subversion and trac or git and redmine where you can control both the project itself, the discussion directing its changes/development, and follow the status of completion.
Nah, this will be for mold builders:)
Planner sounds good, the website's a mess though, old and broken links:/