"You agree that all and any such derivatives and modifications will be owned by Licensor"
Assigning ownership of your own modifications to them seems significantly stronger than forbidding redistribution of your modified version. With this, just getting the examples to run on your own machine is effectively free development for the authors.
Assigning ownership of your own modifications to them seems significantly stronger than forbidding redistribution of your modified version. With this, just getting the examples to run on your own machine is effectively free development for the authors.