The vision of the semantic desktop can be considered as a response to the perceived problems of existing user interfaces.
For example, suppose one downloads a document by a particular author on a particular subject – though the document will likely clearly indicate its subject, author, source and possibly copyright information there may be no easy way for the computer to obtain this information and process it across applications like file managers, desktop search engines, and other services.
Researchers in the iMemex project provide the following query examples:[1] Both of these queries need to parse the file structure, the first one to find a section in a LaTeX document, the second one to find figures and their labels in documents of any format, both of which current OSs don't know how to do.
Ontologies allow the user to express personal mental models and form the semantic glue interconnecting information and systems.
At its most limited state it might be interpreted as adding mechanisms for relating machine readable metadata to files.
To foster interoperability between different implementations and publish standards, the community around the Nepomuk project founded the OSCA Foundation (OSCAF)[3] in 2008.
Since June 2009, the developers from the Nepomuk-KDE communities and Xesam collaborate with OSCAF to help standardizing the data formats for KDE, GNOME and freedesktop.org.
[4] The Semantic Web is mainly concerned with making machine readable metadata to enable computers to process shared information, and the creation of formats and standards related to this.
However the aims of creating a unified interface and allowing data to be accessed in a format independent way are not really the concerns of the Semantic Web.