Web 3.0 – This is the Semantic Web
This JavaOne 2007 BOF was about the coming web, deemed the Semantic Web. The way I would describe a semantic enabled site is to talk about microformats. You can use microformats to annotate a given snippet of HTML to describe the data contained in the HTML. For example, a typical site uses HTML to structure the data, CSS to style the page, but if you want to annotate and describe your data you can use a microformat and add additional attributes to the HTML tags. Simply speaking, you can use a microformat in a web page to describe the meaning and relationship of data. For example, blogs that have a blogroll can add XHTML Friends Network (XFN) data to links to describe the relationship to the link, whether they link to friends you met or coworkers. But instead of using HTML, the Semantic Web is based on Resource Description Framework (RDF). And instead of using XFN, you use Friend of a Friend (FOAF) to describe human relationships. RDF is a way to meaningfully describe your data.
Another format like FOAF is the Description of a Project (DOAP). DOAP is used to describe an Open Source projects with a name, description, SVN info, etc. so that this information can be crawled, indexed, scrapped, and later successfully searched. RDF, like XML, is open in such a away that you can define your own ontologies, and there are many existing ones that will be standardized. Competing ontologies will be naturally selected and standardized by the community. Another interesting RDF format is Beatle, bug and enhancement tracking language.
The speaker started the session by describing a timeline of recent modern computing. He narrowed the PC Era to the desktop of the ’80s, the Web 1.0 was the original World Wide Web of the 90′s, he described the Web 2.0 as the Social Web we currently live in, Web 3.0 will be the Data Web or Semantic Web, and Web 4.0 which is slated for 2020 will be the NetOS or Intelligent Web. In terms of search, he stated that we started Web 1.0 with natural language search, we will soon move to semantic search, then associative search, simple reasoning, and finally to intelligent agents in the Web 4.0.
The speaker said that the Semantic Web, and RDF, can be used to search, archive, and retrieve online content in new ways. He said that the open web would be treated like a massive distributed database. The web is made up of data and RDF can define your data into a database that can be located, reference, and related to other data with URLs.
The speaker also touched on the growing number of semantic tools, a large portion of which are written in Java. The speaker spoke of RDF databases and repositories and SPARQL, a SQL-like query language to search RDF repositories.