Here are some screenshots I took after installing this cool application and opening one of the "scene" files (an XML format) included in the download:
With the mouse, I was able to move around the scene, which is available in 2D, as well as 3D format:
And why was the NetBeans Platform chosen as the starting point of this application? The PDF available on the SourceForge site is quite explicit:
"RaPSor ought to be an extensible, modular, and open-source tool. For portability, we chose the Java programing language, leading to an application running on many architectures and systems, like Unix, Linux, Windows or MacOs. In order to concentrate developers efforts on the business work, we first chose a Rich Client Platform (a.k.a. RCP). Due to the educational aspects of this project, we chose to work with NetBeans RCP, since our students have some courses with it.
Such a platform provides all the redundant programming tools and methods that any developer should write in their application, such as the file and window management, connecting actions to menu items, toolbars... NetBeans RCP comes with many functionalities and provides a reliable and flexible application architecture. Its modularity allows to select the functionalities a developer wants to keep and allows even the users to add or remove new or unnecessary tools. Moreover, users can write new tools, or plugins, using either the NetBeans IDE or another IDE, adding the new tools later into RaPSor."
The NetBeans Lookup API, which enables modules to be decoupled from each other, is also referred to repeatedly in the document. You can read the whole PDF by clicking here (or, if the PDF moves sometime in the future, just go to the RaPSor site on SourceForge).