The LOS Rich Client uses the Netbeans Platform to provide a rich and suitable user interface.
"The NetBeans Platform is a generic framework for Swing applications. It provides the "plumbing" that, before, every developer had to write themselves - the plumbing - saving state, connecting actions to menu items, toolbar items and keyboard shortcuts; window management, etc."
Through its modular architecture the Netbeans Platform is robust and easy to extend, so the LOS Rich Client is.