The Imagine image editor project was developed in 2005 as a NetBeans platform application demo which featured a robust modular architecture for effects, brushes and other painting tools - sort of a photoshop-in-Java applications. It was hosted on kenai.com until that site was shut down by Oracle in 2017, so it lives on here.
I'm hoping to find a backup of it's original web content from java.net to put up here.
In the meantime, it should work and is buildable with Maven.