The underlying working principle of an SDI based on webservices is that it operates on the World Wide Web, also known as the Web. Terms like the Internet and the World Wide Web are often used interchangeably, however they are not one and the same. The Internet is a network, or rather a global system of interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP) to carry a wide range of information resources and services. The most well known application built on top of the Internet is the Web. The Web is a system of interlinked documents connected by means of hyperlinks and accessible via the Internet. Other internet-based applications include electronic mail, file transfer, social networking, and multi-player gaming. In line with this working principle, developers of SDIs have to adhere to two sets of technical standards. The first is the set of technical specifications and guidelines on which the Web is based. The second is the set of technical specifications that address interoperability issues among geo-resources. The standards for the Web are developed by the World Wide Web Consortium (W3C) [1]. The W3C is an international community, led by Web inventor Tim Berners-Lee, that develops the standards needed to ensure the long-term growth of the Web. Standards for interoperability of georesources address a multitude of issues ranging from data capture to presentation and are developed by different organizations, the most of which prominent are the International Organization for Standardization (ISO), through the technical committee ISO/TC 211 [2], and the Open Geospatial Consortium (OGC) [1].