1              Introduction

Semantic Web is becoming more real, there is increasings number of web services, applications supporting RDF data. Moreover, there are variety of valuable semantic data sources like those of mentioned in LinkingOpenData cloud [1]. However, it normally takes a lot of efforts to implement a web site supporting Semantic Web data. Specially, it is unlikely to take Semantic Wen into account when implementing a small website like CMS, blog, forum due to the complexity and cost of implemetation. Hence, inspiring from RSS syndication which is very popular in any website, we implement this demo to give some showcases of RDF syndication. In order to encourage web developer to expose, integrate, syndicate RDF data, this demo will show the light-weight of exposing and integrating data from Joomla!, a CMS platform, without installing any additional database and triple processing library to their websites.

In this demo, we will adopt Triplify[2] script as a Joomla! component to expose data as RDF/JSON feed which can be crawled by Semantic Search Engine (Sindice, SWSE, SWOOGLE) or syndicated by using scripting language. Similar to RSS feed reader, we customize Exhibit to build RDF/JSON feed reader. This feed reader plays the role of  a facet browser which can be embedded to any HTML page as a widget. This feed reader can read RDF data encoded in Exhibit[3] JSON format from these types of resources:  Joomla! exposed RDF data, Semantic Web Pipes and  Sindice’s  SIOC sphere search results.

2           Architecture

Our showcases will be implemented in the architecture as figure 1. In this architecture, data from content publishing platform like Wordpress, Drupal, Joomla can be exposed in RDF format and then processed by Search engine like Sindice[4] or remixing server like Semantic Web Pipes[5]. Thus, such RDF data processing like querying, crawling, indexing, reasoning, remixing, etc are done in those remote servers. On the other hand, the small plugins like Triplify or SIOC exporters will reveal semantic structures encoded in relational database and mak their underlying content available in RDF or JSON.

The processed data or exposed RDF data can be reached by RDF syndication script like Javascript in JSON format. This syndication script will be embedded in cross-site syndicating component of  Joomla which plays the role as RDF feed aggregator and reader similar to any RSS’s one. Syndication script has been used in this architecture is Exhibit. It can feed Exhibit JSON data from multiple and distributed resources and represented in a facet browser. These Exhibit JSON data will be loaded to a graph-based database which can be queried by simple graph pattern expressions. Because all data querying and rendering will be done in browser, the cross-sites syndication component is only responsible for configurating data sources and output views, lens in order to have appropriate syndication to users.

Figure 1. Architecture of light-weight RDF syndication with Joomla

3           Showcases

Our showcases are hosting at http://swm.deri.org/jsyndication/. This website, called JSyndication, is an example Joomla! site installed our Joomla! syndication component. This component will expose content in this site in RDF and JSON. The exposed content can be viewed in rendered HTML page. Similarly, we installed our component to 2 other sites, then we feed content of these remote sites to JSyndication (Joomla RDF feeds). We also has a page called “Favourite RDF feeds” which feed any RDF data sources in Exhibit JSON format.

User can also add some feed to his profile as personal information by create some Semantic Web Pipes remixing his Foaf file and some other information from other resources. For example, author of a news article, named Tim Berner-Lee, create some Pipes which remix his Foaf file, publications from DBpedia,DBLP,ect then submit these Pipes’ URLs to his profile. Thus, when clicking on an author, we will see the “personal information” link which redirects us to author’s syndicated profile.

Another link we can see when clicking an author is “recent Posts”. This link will forward us to the syndication which feeds all of indexed posts of an author from Sindice. These posts were crawled by Sindice from submitted links from Web sites where the author  published his posts.

References

[1] Linking Open Data .http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/ LinkingOpenData

[2]. Triplify http://triplify.org/.

[3] Huynh, D. F., Karger, D. R., and Miller, R. C. 2007. Exhibit: lightweight structured data publishing. In Proceedings of the 16th international Conference on World Wide Web (Banff, Alberta, Canada, May 08 - 12, 2007). WWW '07. ACM, New York, NY, 737-746.

[4] Sindice – The Semantic Web Index. http://www.sindice.com/.

[5]. C. Morbidoni, A. Polleres, G. Tummarello, and D. Le Phuoc. SemanticWeb Pipes. Technical Report, see http://pipes.deri.org/. Nov. 2007.