Zingtree has a simple and robust system for allowing multiple people to work on the same tree.  Here's what you can do:

• Assign a Super User, who can access and view every tree in your organization.
• Add Authors to your organization. Once added, Authors can become Collaborators on any tree.
• Add Collaborators to any tree. Collaborators can either view, edit or grant others access to trees.
• See what trees other people on your team are working on, and request access to their trees.

You can also set up strong passwords or logout authors after a period of inactivity (timeout). Here's how:

1. Go to My Team, My Authors.
2. Click Show Author Security Options.  This appears:
   
3. Set the logout or strong password option.

• How to Add an Author / Collaborator
• How to Delete or Remove Authors from your Organization