Map mashups, Web 2.0 and the GIS revolution

Mashups, composed of mixing different types of software and data, first appeared in 2004 and 'map mashups' quickly became the most popular forms of this software blending. This heralded a new kind of geography called 'Neogeography' in which nonexpert users were able to exploit the power of maps without requiring the expertise traditionally associated, in the geographic world, with cartography and geographic information science, and, in computer science, with data structures and graphics programming. First we suggest the need for a typology of map mashups while arguing that such a typology is premature. We then discuss the need for standards and formats, moving on to questions of security, privacy and confidentiality.We follow this by introducing the key issues of creating spatial data for mashups through crowd-sourcing. To ground this presentation in applications, we explore some classic exemplars from our own and related work with map mashups and portals such as MapTube (http://www.maptube.org/). We then point to extensions to other graphical media, to 3D, to virtual worlds and beyond. In conclusion, we speculate on what all this might mean for GIS software and geographic information science.