Please be aware that there is newer version of documentation available for Webswing. Documentation 24.2
Compositing Window Manager
Compositing Window Manager (CWM) offers better window handling because it renders each window into its own canvas. This enables advanced positioning in HTML document and better canvas-window <=> java-window communication. CWM is the default and only window manager since version 21.1.
CWM documentation is available as part of a migration package.