I've looked at these, but not tried them myself yet:Viking - Main Page - VikingWikiPrune - Activity Workshop - PruneQLandKarte - Welcome to QLandkarte GT/MI think they can display OSM maps, and let you plot tracks, waypoints etc on them, and transfer to a GPS etc. Though I don't think they do autorouting.Or there's Gosmore: Gosmore - OpenStreetMapIt can display OSM maps and do autorouting (including some sort of bicycle routing), but I don't know if it can save the routes to GPX or anything.