This is my summary in the form of a map. Its an attempt to show how all the desktop, web based and mobile products are priced and overlap. There are links through to more detailed pages on the Mindjet web site.
You can buy perpetual licenses for the desktop product MindManager which includes both Windows and Mac licenses. For 5 or more users purchasing Mindjet Software Assurance is mandatory for the first year.
Project Director is web based, has task functionality, allows you to collaborate in tasks and maps, and includes Mindjet Files. Its your task management tool in the cloud accessible from your browser and mobile apps.
The Mindjet subscription license includes the desktop product and Project Director. With this you have a powerful range of functions on your desktop, the ability to collaborate with your maps and manage your tasks.
The Mindjet On-Premise Server is added to a SharePoint installation to allow all users to view the maps and integrate MindManager with SharePoint tasks etc.
Corrections, questions and comments are most welcome.