The number of licenses you need depends on the number of workstations on which vistrax is required. Licenses are concurrent (based on workstations). This means that you may use the licenses on multiple computers. If in isolated cases more parallel access occurs than is licensed for, regular warning messages are displayed. The software is however fully operational. Alternatively, it is also possible to purchase an unlimited Site License, allowing you to use the software on any number of workstations.