The original goal of semantic spaces was to decouple distributed Semantic Web applications in terms of time, space and reference. In the case of Triple Space Computing (Fensel, 2004), the goal was moreover to offer (Semantic) Web services a publication platform that exposes World Wide Web and Web2.0-like interaction patterns to machines; i.e., that enables a "persistent publish and read" paradigm for the collaboration of services. To this end, semantic spaces allow semantic applications to coordinate over a blackboard-style infrastructure without leaving the semantic layer, and secondly it exploits semantic technology to improve the matching and querying behavior of space-based computing systems by means of inference, reasoning and semantic matchmaking. In order to profit from the semant.css of the published data, all stored information must be represented in RDF, and consequently the interaction patterns are based on the exchange and sharing of RDF triples. The original objectives of semantic spaces are very service interaction-driven. The recent emergence of the Linked Data initiative (www.linkeddata.org) and the advent of more mash-up-style and hence data-driven service marketplaces led to a focus on RDF data sharing and interlinking. For this purpose, the semantic spaces implementation that emerged from the SOA4All project is intended to bring the space idea closer to linked data and to serve as a standards-based virtualization layer on top of different standard RDF manipulation and storage infrastructures such as Sesame, Owlim or SPARQL endpoints. The primary intention is to evolve semantic space technology towards a multi-purpose and thus highly horizontal infrastructure for the realization of distributed and dynamic marketplaces of semantic data.
The published semantic spaces release exposes spaces as implementations of an RDF2Go model, which wraps different underlying repositories and RDF management infrastructures that are again exposed via RDF2Go adaptors. As a consequence thereof, semantic spaces provides the standard RDF manipulation methods for adding and querying RDF data.
If a semantic space is configured to run over an Owlim repository (by using the Owlim RDF2Go adapter), spaces moreover offer the possibility to subscribe to graph patterns and to implement notification-based applications.
The semantic spaces implementation published here is released under the GNU LESSER GENERAL PUBLIC LICENSE.
The sourceforge project page can be reached at http://sourceforge.net/projects/semant.csspaces/.
A first alpha release of semantic spaces is available for download on the sourceforge.net project page.
The development of the semantic spaces implementation has been fully funded by the SOA4All project, an European Seventh Framework Programme Integrated Project.
- reto [dot] krummenacher [at] sti2 [dot] at
- gerald [dot] schrempf [at] sti2 [dot] at
- ivan [dot] peikov [at] ontotext [dot] com