Eclipse Graphical Editing Framework

 The Graphical Editing Framework (GEF) provides technology to create rich
 graphical editors and views for the Eclipse Workbench UI. It bundles three
 components:
 .
  * Draw2d (org.eclipse.draw2d) - A layout and rendering toolkit for displaying
    graphics on an SWT Canvas.
  * GEF (MVC) (org.eclipse.gef) - An interactive model-view-controler (MVC)
    framework, which fosters the implementation of SWT-based tree and
    Draw2d-based graphical editors for the Eclipse Workbench UI.
  * Zest (org.eclipse.zest) - A visualization toolkit based on Draw2d, which
    enables implementation of graphical views for the Eclipse Workbench UI.