Is it possible to use Katalon Studio sources as a Java/Groovy development framework like Selenium?

Hello guys,

I know Katalon Studio sources can be checkedout from GitHub.
I think it’s pretty good the pattern used by Katalon Studio separating objects in the object repository from the code (test cases) that manage them, and the same for other features, …

In order to reuse these features yet built in Katalon Studio, I have this question for the community:

Is it possible to checkout the sources and use them as a framework, i.e integrating them in a Java/Groovy project, without using the Katalon Studio IDE ?.
Is there any license restrictions to do this ?
Is there any documentation to learn how to build the sources ?