There is a nice set of tutorials about programming with the Marble library.

One of the chapters is about loading KML files:

http://techbase.kde.org/Projects/Marble/Runners/LoadingKML

Please add another page to this set of tutorials which describes in the same detail how to load .osm files.

While it works the same way the text should be different. And loading OSM files shoul be presented as another example of the previous approach.

• It should be shown how a .osm file can be created by going to www.openstreetmap.org, pressing "Export" and then saving the .osm files
• Choose a suitable zoom level of "Bilbao" http://www.openstreetmap.org/?lat=43.26270908117294&lon=-2.925131320953369&zoom=17 as an example.
• Show how this can be rendered using the same code used in the KML example.
• Show how the code can be compiled.
• Adjust the centerOn and zoomView call accordingly.
• Point out limitations and restrictions of the OpenStreetMap vector rendering.
• Show that the placemarks are clickable and trigger a dialog (via text and a screenshot)

Apply the same mark-up and styling as for the KML tutorial:

• Link to a ready-made Bilbao file
• Link to the API docs for all class names and method names that you describe.
• Keep the Note from the KML page that asks to honor the CC-BY-SA license.
• Adjust the chapter numbers of the tutorials