Two days back there was a longish discussion on the OSM IRC channel about supporting OSM on XSCE, aka on offline, potentially slow devices. Currently it seems if they (XSCE) distribute a pre-rendered set of tiles, and during the discussion (which was mainly about alternatives to distributing tiles) it was mentioned that it would be nice if they, besides a slippy map, could provide a search function.
Now given that disk space idoes not seem to be an issue in the project and keeping in sync with OSM central is not a requirement, it occured to me that Photon might be a viable way of providing a global search function.
Installing it on my PI2 (running Ubuntu 14.04) was surprisingly easy and the only painful part was downloading 30GB of search index over my not particularly fast Internet connection.
[Photon on a PI2](//wiki.openstreetmap.org/w/images/2/24/Photon-pi2.png)
Now perfomance is not great, something like 7 to 10 seconds for a query, ruling out using "search as you type", but bearable for individual queries. Potentially single language search indices would be faster, but that would needed to be tested.
Naturally alternative approaches for example using mapsforge might be better and would get around the requirement for prerendered tiles, however it is not clear if a global map would actually be feasible.