BaseCamp is software from Garmin for viewing maps, waypoints, routes and tracks, and transferring them to or from a Garmin GPS device. It is available to download free of charge for Windows or Mac OS X.
In many ways it replaces MapSource (Windows) and Roadtrip (Mac OS), though it currently lacks a few features that are present in MapSource. Also it works somewhat differently, eg all waypoints/tracks are added to a single database, not separate files. Though it can import or export files in GPX, TCX or GDB format.
As standard, the BaseCamp download includes a not very detailed global basemap. BaseCamp uses the same maps as MapSource, so any OSM maps installed in MapSource will also be installed in BaseCamp. It can also display maps stored on a GPS device or memory card.
Running Basecamp 4.2.5 on Linux is possible using wine, see Maps & Navigation > Basecamp > 4.2.5.
- OSM Map On MapSource - instructions should also work for adding maps to MapSource
- OSM Map On Garmin/Download - maps with a MapSource installer will also install in BaseCamp (on Windows)