Marble is an application that displays a view of the earth.  It is
both a valuable application in its own right, but also an example
program that shows how you can use the Marble widgets in your own
applications.

The Marble application makes use of the following classes and widgets:

1. MarbleWidget, the main widget in any application using the Marble
   framework.  This widget displays a view of the earth or any other
   globe, depending on which dataset is used.  The user can navigate
   the globe using either a control widget, e.g. the MarbleNavigator,
   or the mouse.

2. MarbleModel, the data storage class that holds the data that is
   visualized in the MarbleWidget. The MarbleModel is created internally
   and can be accessed using the model() method.

These two classes provide the core of the classes that comprise the
Marble framework.  You can use only them and get a very capable
application.

Homepage:
https://marble.kde.org/
