ArcGIS!

QGIS, formerly Quantum GIS, is a user friendly open source Geographic Information System (GIS) licensed under the GNU General Public License that runs on Linux, Unix, Mac OSX, and Windows and supports numerous vector, raster, and database formats and functionalities.

GRASS GIS (Geographic Resources Analysis Support System) is an open source, free software (FOSS) Geographical Information System (GIS) with raster, topological, vector, image processing, and visualization functionality. Used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization, GRASS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies. »

PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRIs SDE or Oracles Spatial extension. PostGIS follows the OpenGIS "Simple Features Specification for SQL" and has been certified as compliant with the "Types and Functions" profile.

Blue Spatial is an ESRI Geoservices REST Implementation. Blue Spatial is a drop in replacement for ArcGIS Server that works with all ESRI API's and ArcGIS Desktop. Blue Spatial was created as an alternative to ArcGIS Server for organizations that have existing investments / apps built with ESRI technology but would like to reduce the ongoing expense of ArcGIS Server and or ArcGIS Online. Blue Spatial can also be used by customers that want an ESRI compatible, inexpensive, lightweight and easy to use system for their spatial infrastructure. See how easy it is to setup and use by watching the screencasts. »

MapET Spatial Feature Server is software that makes your geographic information (vector data) available to others in your organization and optionally anyone with an Internet connection. This is accomplished through web services, which allow a powerful server computer to receive and process requests for information sent by other devices. MapET Spatial Feature Server opens your GIS to devices that can connect to web services.

gvSIG is a Geographic Information System (GIS), that is, a desktop application designed for capturing, storing, handling, analyzing and deploying any kind of referenced geographic information in order to solve complex management and planning problems.

MapInfo Professional is a powerful, functionally rich desktop mapping application from Pitney Bowes MapInfo, designed to enable organisations to solve business problems that have a geographical element.

Supergeo Technologies Inc. is global leading GIS software & total solution provider. With series GIS products covering from desktop, mobile, server to developer SDK, SuperGIS has been utilized more than 100 different countries.

OpenLayers is a high-performance, feature-packed library for all your mapping needs.

uDig is a GIS software program produced by a community led by Canadian-based consulting company Refractions Research. It is based on the Eclipse platform and features full layered open source GIS. It is written in Java and released under GNU Lesser General Public License.

Creating web map applications with Mango is quick and easy. All you need is a web browser and your data. What you won't need are any programmers, expensive servers, software licenses or an accountant to figure out the pricing.

Mapline is the simplest mapping software on the planet! Be empowered with map visualizations from Excel spreadsheet data to optimize logistics, enhance market planning, identify growth opportunities, or mitigate market risks. Create your first map now!

The GEOCONCEPT solution was designed first and foremost to respond to expectations of users who wanted to leverage the power of geographical data to the fullest.

MapWindow is a fully free and open source geographic information system project. It includes an open source programming component, MapWinGIS ActiveX, and an extensible desktop application that supports plug-ins written in .NET (C# and VB.NET). The most recent effort, MapWindow 6, includes a fully C# programming library that is intended to serve as an alternative to ESRIs ArcObjects platform.