TNTAtlas
TNTatlas is a free Geodata viewing tool for Mac OS X and Windows. Geodata files currently supported include shapefiles, DWG, DGN, DXF, JPEG, JP2, TIFF, GeoTIFF, PNG, ECW, and MrSID formats. TNTatlas also has features for querying, measurement, printing, sketching of the displayed geodata.


