Semantic Web

The Semantic Web is an initiative of W3C to provide a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF), which integrates a variety of applications using XML for syntax and URIs for naming.  The Semanitc Web and Open Linked Data share a common set of standards (and may well be the same thing).

"The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001

Learn more from the W3C Web Pages on the Semantic Web

Primary Technologies
The primary semantic web technologies - RDF and OWL are of primary interest to as a distributed metadata repository, as components of shared concepts which represents a vision of complex systems that are defined and provisioned based on high-level models, as well as a source of semantically rich models.

Semantic Grounding of Data & Architectures
These Ontologies are seen as ways to tie formally unrelated models and architectures together. This is referred to as "semantically grounding" an architecture. By semantically grounding an architecture, terms and concepts in that architecture are tied to reference Ontologies that are then used to bridge between architectures using semantic tooling.