There are hosts of other Data Visualization and GIS platforms that are open source, or that have a free version. A few are listed here, if you want to take a deeper look.
OpenLayers is a pure JavaScript library for displaying map data in most modern web browsers, with no server-side dependencies. OpenLayers implements a JavaScript API for building rich web-based geographic applications, similar to the Google Maps and MSN Virtual Earth APIs, with one important difference – OpenLayers is Free Software, developed for and by the Open Source software community.
D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS. D3’s emphasis on web standards gives you the full capabilities of modern browsers without tying yourself to a proprietary framework, combining powerful visualization components and a data-driven approach. Warning: You need to know how to deal with Javascript objects to work with D3.
GRASS GIS, commonly referred to as GRASS (Geographic Resources Analysis Support System), is a free and open source (GIS) software suite used for geospatial data management and analysis, image processing, graphics and maps production, spatial modeling, and visualization. GRASS GIS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies. It is a founding member of the Open Source Geospatial Foundation (OSGeo). GRASS can work closely together with QGIS, generally with more applications in the sciences.
Harvard WorldMap is an open source mapping platform developed to lower barriers for scholars who wish to explore, visualize, edit, and publish geospatial information. The WorldMap system attempts to fill a gap between desktop GIS which is generally light on collaboration, and web-based mapping solutions which generally don't support the inclusion of large datasets.
WorldMap enables researchers to:
