QGIS
QGIS is a free and open source Geographic Information System (GIS) available on Windows, Mac, and Linux. It allows users to view, create, and export maps for a variety of uses and from a broad range of sources.
Installation
Choose your operating system from the Download page. You may be sent to an instructions page, as in the case of Linux, or you may see a file downloading. Look for links to installation instructions on the download page if instructions aren’t published.