Many people may not have need of a full-blown suite of GIS software, wanting, perhaps, simply to view data or run simple queries. ESRI offers the ArcGIS Online Map Viewer, a free "lightweight" GIS data viewer, for such users. The online, cloud-based ArcGIS Online Map Viewer may be used for a variety of display, query, and data retrieval functions and supports a wide variety of standard data sources.
Use Google Fusion Tables through (Google Docs) to upload a spreadsheet and display your data on a Google map. You can then embed your Google map in a document or website.
GeoCommons is a free collection of data uploaded by the public. The data often come from public and open government sources. The archive features over 150,000 datasets as GeoJSON stored in Github and available to preview, download or explore using the online GIS platform ArcGIS.com.
QGIS allows you to visualize, manage, edit, analyze data, and compose printable maps. The program runs on Linux, Unix, Mac OSX, Windows and Android and supports numerous vector, raster, and database formats and functionalities.
GRASS is a free “GIS, image processing system, and graphics production system. GRASS contains over 350 programs and tools to render maps and images on monitor and paper; manipulate raster, vector, and sites data; process multi spectral image data; and create, manage, and store spatial data…GRASS can interface with commercial printers, plotters, digitizers, and databases to develop new data as well as manage existing data”.
A free program for desktop GIS data access, editing, and viewing.
View, print and annotate Design Web Format™ (DWF™) drawings.
Allows viewing of SHP, MIF/MID, cgf, and DBISAM files.
Enables basic viewing and saving of digital imagery.
Use MapWindow for manipulation, analysis, and viewing of geospatial and attribute data in several standard GIS data formats.
The software views numerous raster (TIFF/GEOTIFF, MrSID®, BMP, SPOT, JPG) and vector (SHP, E00, MIF, DXF, DGN, TIGER) formats. Imports TatukGIS projects as well as most projects created with the ESRI ArcView® or MapInfo Professional®.