MAPS.ME is an open source offline maps application for iOS and Android. It provides detailed offline maps of the world and is built on top of crowd-sourced OpenStreetMap data, with its own binary format for map styles.
a free and open map of wireless communicating objects
openBmap collects data and provides open maps and statistics of all communicating objects: cellular antennas, wifi hotspots.
All softwares from back-end to client are open-source under AGPL v3 license.
This is an application for the Palm Pre (or Pixi) that will convert between the Palms native Latitude and Longitude co-ordinates to BNG co-ordinates. It will also back convert. Use WebOSQuickInstall.