ESRI offers free Web mapping APIs
Because the APIs are part of ESRI’s Web infrastructure, users will have access to ArcGIS Online map services for imagery, street maps and topographic maps, as well as services for routing, geocoding, demographic analysis and more. Organizations can spatially enable their databases without the need for maintaining an expensive infrastructure. For example, a city government might deploy two different types of applications: an internal-facing executive dashboard that allows officials and managers to track capital improvement spending, and an external-facing application for citizens to contribute their concerns and suggestions regarding those improvements. Both applications could be deployed at no cost.
To access downloads and get more information about ArcGIS Web mapping APIs, visit www.esri.com/apis.