The TamoGraph license agreement allows two activations with certain limitations. A second copy can be installed and activated (on a desktop, for example), but only if both devices belong to the same person, and the two installations are not used at the same time.
The license is perpetual, and includes one year of free product updates and technical support. After one year, the user can either keep using the product without installing further updates (TamoGraph won't stop working) or renew their license when convenient and get one more year of free product updates and technical support.
For further details, see the TamoGraph upgrade policy.