Open Source C Mapping Software for Linux

Viking is a free/open source program to manage GPS data. You can import, plot and create tracks, routes and waypoints, show OSM, Bing Aerial and other maps, geotag images, create routes using OSRM, see real-time GPS position (not in Windows), make maps using Mapnik (not in Windows), control items, etc. It is written in mostly in C (with some C++) & the GTK+3 toolkit. Viking is currently dual managed - with a corresponding Github presence at: https://github.com/viking-gps/viking Where you may find it easier to view the code and raise issues there too.

See https://www.openorienteering.org/apps/mapper/

Modular, touch screen friendly navigation system with GPS tracking, realtime routing engine and support for various vector map formats. Works on a wide range of devices, from computers to smartphones.

NOTE: Code commits are FROZEN on SourceForge: New code is now at <http://github.com/Xastir/Xastir>. Real-time tracking & messaging of stations via radio/internet APRS data streams, w/125 map formats supported. Linux/FreeBSD/Solaris/MacOSX/Windows in any of 7 languages. Can also be used for mobile mapping w/GPS. MAILING LISTS ARE AT: PROJECT->WEB SITE.

A bike information system for cyclists in Berlin and Brandenburg (Germany) with a map view and a routing engine. There's a graphical interface (based on Perl/Tk) as well as an Web interface. Source code may be found at Github: https://github.com/eserte/bbbike/

Gpsdrive is a car (bike, ship, plane) navigation system. Displaying your position on a map and a lot of other functions are implemented. It works with vector maps from http://www.OpenStreetMap.de/