Working on Tom's Planner with a team
Tom's Planner is the ideal starting point for any team that is working on a project together and wants to create and manage a project plan online.
So if you received an invitation to collaborate on a schedule, a free account will suffice. If you want to invite others to collaborate on your schedules you will need a paid account, you can then invite team members, clients or other parties and assign read-only and/or edit rights.
If you want to keep it simple and want others to see the project plan without having to sign up with Tom's Planner, you can choose to publish your project schedules online and others can keep up to date by checking the url. Every time changes are made the published schedule will automatically be updated as well.