Marble provides so called "Online Services" which allow to visualize data on the globe. These Online Services are implemented as plugins. There is a tutorial available which shows how to create such plugins:

Online Service Tutorial

This task is about creating such an Online Service. First you should compile Marble from the sources:

Compiling tutorial

Follow the instructions of both tutorials and report and improve all errors that you come across.

Once you have a basic Online Service running extend it to do something useful.

You could e.g. create a Postal Code Online Service plugin. In order to implement this you can use

Geonames.org

The service would display the postal codes on top of the map in bold letters. Of course you can also suggest a different kind of service.

The plugin doesn't need to have a settings dialog or about dialog. Just the basic functionality is supposed to work.

Expected result: A new Online Service Plugin that provides new functionality to Marble.