I have built Marble Widget within my QT application. I am using version 0.12 of the source code. It seems as though there is memeory leak happening when I add a rather large KML file. The program memory used seems to grow without bound. 

Here is how I add the KML file:

QFileInfo inputFile( "WorldBorders.kml"); 
m->model()->addGeoDataFile(inputFile.absoluteFilePath()); 

kml file: http://code.google.com/p/kml123/downloads/detail?name=World%20Borders.kml

Also, as per http://forum.kde.org/viewtopic.php?f=217&t=108027&p=251448#p251448:

Earthwings : "I just did the following:

    Open marble with --enableFileView parameter
    Note memory usage
    Open http://code.google.com/p/kml123/downloa ... orders.kml
    Toggle checkbuttons in the file view tab, watch memory usage
    Close .kml file in the file view tab, note memory usage


Memory was ever increasing and didn't go down after closing the file, so I'd say you're right that there is a memory leak, or at least the .kml file is kept in memory even when it is not needed anymore."