This is a brief post with one purpose: to clarify the meaning of the term "semantic." It has suddenly become chic to label every new app as somehow "semantic" but what does this mean really? Are all "semantic" apps part of the "Semantic Web?" What is the criteria for something to be "semantic" versus "Semantic Web" anyway?
It's pretty simple actually. Any app that can understand language to some degree could be labeled as "semantic." So even Google is somewhat of a semantic application by that criterion. Of course some applications are a lot more semantic than others. Powerset is more semantic than Google, for example, because it understands natural language, not just keywords.
But for an application to be considered part of the "Semantic Web" it has to support a set of open standards defined by the W3C, including at the very least RDF, and potentially also OWL and SPARQL. These are the technologies that collectively comprise the Semantic Web. Supporting these technologies means making at least some RDF data visible to outside applications.
I'm not sure if Powerset is doing this yet, nor whether Freebase is doing it yet, but they should (and I'm guessing they will). Twine, my company's application, is using RDF and OWL internally within our app and we are also exposing this via our site (although we are still in private beta so only beta participants can see that data today). Other companies such as Digg are already making their RDF data visible to the public. Any application with at least publishes RDF data can be considered to be both semantic and part of the Semantic Web.