Figure 4

Resource Query Graph (RQG). Clients query a discovery server for data and service providers using the same canonical graph structure and sharing the same publicly available ontologies used by providers when the providers described their resources. The query in the figure is asking "Get me all resources that map anything to a taxa:Taxa". Anyone can do a HTTP GET on taxa:Taxa to see its definition. Architecturally, more complicated queries can be built by using additional OWL DL assertions, replacing blank nodes with individuals, or using concepts from other publicly available ontologies. Currently, the discovery server running at http://sswap.info does not support all OWL DL embellishments but implements semantic searching by returning all services that are subclasses of the sswap:Resource with super classes of the sswap:Subject and subclasses of the sswap:Object. For programmatic access see http://sswap.info/sswap/resources/queryForResources/inputForm.jsp.