LabMathX requires a serial number and user name. If you pay the fee, then you will be sent 3 licenses. This permits you to install LabMathX on at least 3 different Macs on which you are the Admin. Once installed, it is keyed to the hardware and copies will not be functional. The user name and serial number are tied also. If you install LabMathX on a 4th Mac that has user differences, it won't work unless you contact us with a reason. Legitimate reasons exist for your doing so (buying a new Mac). If so, email us and we'll send a new serial number. We do not spy on your Mac and we don't require a network connection. LabMathX is copyrighted by Thomas L. Ferrell and Sky Coyote and may not be copied or distributed in any form without permission of these authors. No portion of the user interface may be duplicated. BACK