Did you ever wondering who (companies or developers) are using Netbeans Platform as their platform of choice ? You will be surprised if you check this Netbeans Platform Screenshot Showcase.
There are a lot of them from various categories: Aerospace & Defence, Oil & Gas Services, Geospatial, Bio & Chemoinformatics, Scientific Modelers, Monitors, & Analyzers, Healthcare, Network Management & Communications Systems, Retail, Graphic Design & Image Manipulation, Music & Entertainment, Software Development.
So let’s me iterate again (or read this instead) why it is good idea to use RCP (Rich Client Platform) vs Java plus libraries. For me Rich Client Platform (RCP) is a set of libraries with tight integration, it was build from ground up to work together as a platform so other application can be build or run on top of it. In contrast, Java plus libraries is a mix and match of libraries to support the application eg: give new features, etc.
One main problem with the mix and match style is because that libraries may not be designed to work together, they could be excellent library on its own, but once they integrated together to form a single system (an application), sometimes it may require some glue or bridge code to make them work together. On the other hands for RCP, these set of libraries will work together since it is designed that way from beginning.