"Although the Semantic Web (SW) is still very much in its infancy, there is already a lot of data out there which conforms to the proposed SW standards (e.g. RDF and OWL). Small vertical vocabularies and ontologies have emerged, and the community of people using these is growing daily.... "
RSS (Rich Site Summary, RDF Site Summary, or Really Simple Syndication) has been around since the mid-1990s. Over the years, several variants of the RSS format have popped up and several claims have been made about its ownership. Despite these differences, RSS never ceased to serve its usefulness in distributing Web content from one Web site to many others. The popularity of RSS gave way to the growth of a new class of Web software called the feed reader, also known as the feed aggregator. Although there are several commercially available feed aggregators, it's easy to develop your own feed aggregator, which you can integrate with your Web applications. You'll appreciate this article's fully functional PHP code snippets, demonstrating the use of PHP-based server-side functions to develop a customizable RSS feed aggregator. In addition, you'll reap instant benefits from using the fully functional RSS feed aggregator code, which you can download from this article.
more intelligent applications for aggregating, searching, and browsing
Using the Common Tag format
a range of services that help publishers and bloggers
a standard and extensible set of tags
services that help users discover tagged content
tools to relate those tags to web page content
automated tagging tools like those offered by Zemanta
discoverable through a single tag
More discoverable
Social tagging services like Faviki and Zigtag
allow end users to tag content using the Common Tag format
Services like DERI's Sindice.com provide developers with tools to find and incorporate related content into their applications using Common Tag
Yahoo and Google have begun reading RDFa--the markup standard used by the Common Tag format
More connected
Common Tag metadata connects concepts
AdaptiveBlue's Glue service plans to use the Common Tag format to help connect end users to other people with similar interests and to other related content
a developer might use Freebase's development tools
to create a simple application that takes an article