Upgrades are free for any versions that have the same major revision number. For example, if you were to license version 126.96.36.199, then any subsequent release with the same major revision number, such as v 188.8.131.52 or v 184.108.40.206, is a free update.
The program files are identical for the licensed and evaluation versions of Keyboard Express.
In the event of a new major release (i.e. v5.0), an upgrade fee will be required.
If you are upgrading from Keyboard Express 3.x, please read the Upgrading from Keyboard Express 3 notes.