Open

• OpenCellID, database of only cell towers The data are available under the "Creative Common Attribution-Share Alike 3.0 Unported" license.

• OpenBMap, database of cell/WiFi GPL version 3 - Creative Commons License creative commons Attribution-Share Alike 3.0 Unported (data from opencellid.org are imported on a regular basis)

Commercial

• Skyhook
• Google Location Services
• Navizon

Other

• Wigle