## 2 Volunteered Geographic Information
### The OSM Project  
The OSM project was initiated in 2004. Its main database and web services are hosted on a number of servers at University College London. Additional server infrastructure was established through several donation rounds. All servers and interfaces to create and share OSM data are mainly developed and administered by volunteers [48]. The project's goal is sometimes described as \"building a global map\" [49]; however, the main aim of the project is to build a freely available database with geographic information, which can, of course, be used for mapping purposes, but also for navigation or other applications. The OSM Foundation (OSMF), an international not-for-profit organization, has been established to encourage the growth, development and distribution of free geospatial data and to provide geospatial data for anyone to use and share [50]. Additionally, the OSMF is divided into \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Attribute** & **Map maker** & **Here map** & **Map share** & **Waze** & **Wiki** & **OpenStreet** \\  & **(Google)** & **creator (Nokia)** & **(TomTom)** & **Waze** & **mapia** & **Map** \\ \hline Initiated in & 2008 & 2012 & 2007 & 2008 & 2006 & 2004 \\ \hline Number of Users or & & & & & & \\ registered Members & N/A & N/A & 60 \({}^{1}\) & 45 \({}^{2}\) & 1.9 \({}^{3}\) & 1.3 \({}^{4}\) \\ (in million) & & & & & & \\ \hline Active Contributors & & & & & & \\ per month in 2013 & 40,000 \({}^{5}\) & N/A & N/A & 12–13 & & \\  & & & & & million \({}^{9}\) & N/A & 20,000 \({}^{4}\) \\ \hline Coverage (number of & & & & & & \\ countries) in 2013 & \(>\)220 & \(>\)120 & \(>\)90 \({}^{6}\) & World & World & World \\ \hline License & Property of & & & & & \\ Google & Property of Nokia & Property of & Property of & & & \\  & & & & & & \\  & & & & & \\ \hline Data downloadable & No & No & No & Yes \({}^{7}\) & Yes \\ \hline \hline \end{tabular} Notes: \({}^{1}\) the number of enabled devices; \({}^{2}\)[45]; \({}^{3}\)[39]; \({}^{4}\)[46]; \({}^{5}\)[47]; \({}^{6}\) the number of countries for which map data is available; \({}^{7}\) only via a web-API.  
\end{table} 
Table 1: Comparison of volunteered geographic information (VGI) projects. ODbL, Open Database License; API, application programming interface; N/A, not available; CC BY-SA, Creative Commons Attribution-Share Alike. several working groups [51] that support the project in specific areas of interest. For instance, the Operations Working Group plans and maintains the OSM API and servers. At the time of writing, the OSM project had almost 1.4 million registered members [45], who contributed almost 2.1 billion points and 220 million lines, which are partially based on 3.6 billion GPS points that have been uploaded. Similar to other online communities, such as Wikipedia, only a small percentage of those volunteers actively contribute data on a regular basis, as we will discuss in more detail at a later point in this article. To be able to contribute data to the OSM project, the potential member has to register and create an account. In contrast to other VGI projects, the newly registered member can add, modify or delete geographic objects in the OSM database right after the registration process, whereas, for instance, in Google Map Maker, the edits made by new members are reviewed first. This relatively open approach to data contributions in OSM is described as one of the major benefits of the project [52]. The collection of geo-information by online communities is oftentimes described as a bottom-up approach [12]. In the case of the OSM project, however, different data contribution types need to be distinguished. In the first few years of the project, most contributors collected the geo-information by utilizing GPS-enabled handhelds. However, between 2007 and 2011, the Internet company, Yahoo! [53], allowed the OSM project to trace data from their satellite imagery, and a similar agreement could be established with Microsoft Bing Aerial Imagery [54] in November 2010.