OnMars add-on released
Mars Global Surveyor, Mars Observer Camera Narrow Angle (MOC_NA) composite. A 0.5 arc-second composite of more than 50,000 high resolution images of Mars, located between 75N and 75S. It is an uncontrolled mosaic, the images are placed on the global frame based on the best known location, using a simple warp. Location errors are common, but it does match MDIM and MOLA rather well. The mosaic contains more than 300GB of raw image data, and images are still being released, so this layer will be updated if possible.
See the OnMars add-on page for more details.