Even the download can be installed on more than 1 computer. It is about 1.5 GB and you would have to transfer it via USB or such.
Have used it for years, including the GPS. Use it on a 12 inch Tablet. Found a dash mount that works.
As others have said. It has basic and advanced features. It will take you a while to learn how to use the POI Megafile, but it is worth it. When you learn the most common things you use, you can save with only those categories of POI turned on. Again, no clearance and load data. No internet required. I update mine at home before hitting the road. No street level view. As stetwood pointed out, there is a lot you can do to organize and use external tools and (Garmin) GPS files.
This is a good tool.