Some of GEF's features are:
* A simple, concrete design that makes the framework easy to understand and extend.

* Node-Port-Edge graph model that is powerful enough for the vast majority of connected graph applications.

* Model-View-Controller design based on the Swing Java UI library makes GEF able to act as a UI to existing data structures, and also minimizing learning time for developers familiar with Swing.

* High-quality user interactions for moving, resizing, reshaping, etc. GEF also supports several novel interactions such as the broom alignment tool and selection-action-buttons.

* Generic properties sheet based on JavaBeans introspection.

* XML-based file formats based on the PGML standard (soon to support SVG).