Ozgur Akan's Blog: Why I choose SWT against Swing: "# If one needs to develop data entry applications like forms etc, it is best to use SWT. This gives Windows users (who are basically non-tech, business users) the familiar feel of a Windows UI. These people don't like surprises period.
# If one needs to develop utility applications like download managers, media players, p2p clients, mail clients, standalone text editors etc, one should use SWT. These are mass downloadable apps, and are used primarily by non-tech users. As case in point is the Azzerus Bit Torrent Client.
# If one needs to develop a complex gui like a BPEL modeler, or a CAD modeler, then lot's of custom widgets may need to be built. Believe me developing custom widgets with Swing is a lot easier than SWT."