QGIS is open source and very powerful desktop GIS software. It is similar to ArcGIS but not to the full scope of capability as the paid ESRI software. But the price is right, and it still has a wide variety of capabilities. It can also be manipulated with Python code. There is a vast trove of documentation on it and many useful books on how to use it.

You can download and install QGIS from the project site (http://www.qgis.org/en/site/forusers/download.html). If you are unable to get ArcGIS, make sure to keep QGIS handy. QGIS was used to create many of the images in this book. You can use both QGIS and ArcGIS to connect directly to geospatial databases, such as PostGIS and Oracle. The following image shows an example of what can be created with QGIS: