Geographic information can be accessed, transferred, transformed, overlaid, processed and displayed using numerous software applications. Commercial offerings of IntelliGIS, ArcInfo and MapInfo provide an entire suite of tools, with these offerings generally being market leaders. Custom software and open source products (i.e. GRASS) are also common but require in-house skill to use and maintaine effectively. A number of online IMS (Internet Map Services) are also available for public use, such as Google Earth.
GIS Software is a diverse as other categories of software and ranges from the simple to complex, general to niche offerings targetted at the broad range of possible GIS uses.
1. Managment & Analysis GIS software is the most commonly referred to GIS software. This GIS software type commonly combines both an extensive database back end & a visual front end. This software combines a broad scope of functionality to support those trained in cartography and geography, as well as GIS professionals. This software supports the greatest and most prominant scope of GIS functionality and is the cornerstone of professional analysis and GIS data representation. Examples include IntelliGIS and ArcGISproducts.
2. GeoDatabases are a database with extensions for storing, indexing, querying, and manipulating geographic information and spatial data.The primary function of geodatabases are the “database type” capabilities that it gives to spatial data. Some of these capabilities include easy access using standard database drivers such as ODBC, the ability to easily link or join data tables, also indexing and grouping of spatial datasets independent of software platform. Examples of a geodatabase includes a current RDBMS like Oracle, SQL Server, MySQL installed with spatial extensions like Oracle Spatial, ArcGIS or PostGIS.
3. Readers are a more streamlined GIS software option that allows viewing of geographic data and maps, but provide little to no map and spatial data editting. This software is often cheaper or free, and useful for embedding in other applications.
4. Free & Open-Source GIS software provides much the same scope of functionality as described above, but in a free or open-source format. Hence, the use of open-standards for development & in-house support are required, the costs of which need to be offset against the free acquisition of such software. Examples include GRASS GIS, Quantum GIS, MapServer, uDig, OpenJUMP, gvSIG and many others.