Hey guys!  One of the really great features of Marble is that it can be used offline, but large amounts of map data can be extremely large, and there's not really a good way to do bulk downloads.

To make this easier, a feature could be added allowing either png or webp tiles, choosing png if available, along with a second feature defining a simple .zip format for packaging complete complete maps, tiles, metadata, points of interest, and all.

A quick test of this shows that a lot of the larger OSM tiles can still be compressed 3x or more, despite not being photographic, with most seeming to be around 2x, with decent enough quality for something largely functional like a map.

The files could then be distributed via Torrents much like Kiwix .zim files currently are.  This would even enable some educational distros to include low-res maps out of the box!