I'm new here, mostly because it didn't seem possible to use the maps here without a windows or mac computer. I use a linux desktop and have installed quite a few open source maps on my GPS in the gmapsupp.img format. I have a mac on my lap now so I just installed my 1st map from here. I'm wondering why the dependence on the PC and mac tools when the map files could be in .img format. It's trivial to install these on the GPS from any OS.