TLA Systems today released DragThing 4.5, a major update to its popular dock application for Mac OS X and earlier. Version 4.5 features improved support for Mac OS X “Jaguar” (including 10.2.1), new hot keys to control individual docks, support for custom sounds on Mac OS X, improved performance, and more. DragThing 4.5 is a free upgrade for existing registered users of DragThing 4, US$10 for registered users of previous versions, and $25 for new users.