There is no zoomlevel limit in the GTK GUI, as simple as that. This makes modRana GTK very future proof and ready to support atomic-scale map layers once (if ever ? :P) they become available.

Regarding the QML GUI, its is quite possible it is some hardcoded zoomlevel limit, maybe even from AGTL, which is the original source for the PinchMap element used by the modRana QML GUI.

This could be definitely improved upon, as since some time the modRana map definition file lists maximal zoomlevel for layers, so that could be used to set the lowest zoom, based on currently displayed layer. I guess also some sort of override might should be available, so that you can zoom in to arbitrary zoomlevel - for example to work with closely situated POIs that are overlaid on low zoomlevels (well, once they are implemented in QML GUI).

So I'll probably leave it without limit on GTK and use the max-zoom-per-layer with override in QML.

The Monav data packs (BTW, I should really finally fix their updating) are currently used only for offline point-to-point routing.

Actually It does not even support offline address-to-address routing - the Monav preprocessor can create an address database, but there is no external interface to it. The database format is described here:
http://code.google.com/p/monav/wiki/...TournamentTrie

Any takers for Python parsing module (ctypes ?) so that modRana can use it for offline address lookup ?

Monav does support some sort of vector map rendering, but that is unfortunately internal functionality without any external interface (like for example telling Monav to render tile images), that modRana can use.

The current plan for vector map rendering is to use the Kothic Python+Cairo MapCSS using map renderer, but suggestions for alternative (preferably portable) renderers are also welcome.