In Web 1.0, standards allowed information to describe how it could be presented, exchanged, and repurposed. This created a world of shared information. However, as the Web grows in size and scope, it becomes harder to find what we want, to identify like-minded people and communities, and to have applications work together smoothly.
Web 2.0 will become more useful by creating a meaningful semantic Web. Researchers are working on the standards, taxonomies, and other ontologies needed to create a semantic Web. These standards will enable information to describe its own origin, scope, purpose, and even meaning. This will create a world of more intelligent services and content, both for human-machine interchange and machine-machine synchronization.
The semantic Web will add meaning to our current simplistic matching of mere strings of characters against buckets of words. This is a complex issue, because meaning is organic, determined by use, and a moving and context-dependent target.
The current debate: should meaning on the Web be (1) evolutionary, driven organically through the bottom-up human assignment of tags or (2) does it need to be carefully crafted and managed by a higher authority, using structured representations with defined semantics? Evolutionally (bottom-up) tagging is helpful with shared, formalized vocabularies (top-down) for interoperability and machine support.
Interesting sites: Flickr.com, del.icio.us, Upcoming.org
There are at least two semantic Webs:
1. A Web of data (exposed databases of data). Tagging may not be helpful here.
2. Enrichment of the human-readable Web. Tags will be a powerful way to improve meaning.