You could consider donating server space and bandwidth to Openstreetmap projects. There's a wiki for OSM but it's quite confusing at times. Then there's Nominatim, the name search; it requires lots of computer resources. Open source routing from OSM data can be done with OSRM, which is quite fast.
Perhaps extracts of OSM data for downloading would be nice, eg. just roads, waters; see what's already available.