XPOR System Modeller is not limited by the number of times you can install it. Typically it is installed by a licencee on many machines, often with many discrete user accounts. Yet all user accounts can work on any aspect of the Model.

This can cause problems when two users are working on the same feature - e.g. a Form.  It's a very rare occurrence and hasn't really troubled people.  However, XPOR has now introduced record locking in System modeller.

If a user opens a form (or XFLOW or Datasource or ...) then that record is locked.  Subsequent users Other users can no longer edit it - only view it, until the administrator who is working on it has finished and closed it.