Project Repository: https://projects.eclipse.org/projects/tools.gef
Eclipse Zest is a visualization toolkit for graphs. It is based on SWT / Draw2D. Zest supports the viewer concept from JFace Viewers and therefore allows to separate the model from the graphical representation of the model.
I developed Zest as part of my PhD thesis at the University of Victoria. The goal of the project was to create a visualization toolkit that could be used to visualize large graphs. The toolkit was designed to be extensible and to support multiple layout algorithms. The toolkit was also designed to be used in an Eclipse RCP application, but it could also be used in a standalone SWT application.