VLSolutions has released version 2.1 of its Swing docking framework VLDocking. They write in, "This release brings many enhancements to VLDocking, the most important ones beeing: support for Compound Dockable Containers ("tabs which contain splits which contain tabs..."), support for Multiple-Desktop Applications, sharing (or not) dockables between desktops - with full drag and drop control, anchor constraints to fix dockables on assigned borders, and a new event model for precise dockable action listening and vetoing."