Soprano is a software library that provides an object-oriented C++/Qt4 framework for RDF

Resource Description Framework

The Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...

 data. Soprano was created as a sub project under the NEPOMUK

NEPOMUK (framework)

NEPOMUK is an open-source software specification that is concerned with the development of a social semantic desktop that enriches and interconnects data from different desktop applications using semantic metadata stored as RDF...

 project and forms a part of the semantic desktop in KDE Software Compilation 4. Soprano functions as a repository to store information generated by the NEPOMUK server (like ratings, tags or comments), which will then be indexed by Strigi

Strigi

Strigi is a desktop search daemon, which is operating system-independent and desktop-independent. Strigi was initiated by Jos van den Oever. Strigi's goals are to be fast, use a small amount of RAM, and use flexible backends and plug-ins. A benchmark as of January 2007 showed that Strigi is faster...

 for better search results..

Soprano comes with support for redland

Redland RDF Application Framework

Redland is a set of free software libraries written in C that provide support for the Resource Description Framework , created by Dave Beckett .The packages that form Redland are:...

 and Sesame2

Sesame (framework)

Sesame is an open-source framework for querying and analyzing RDF data. It was created, and is still being maintained, by the Dutch software company . It was originally developed as part of the "On-To-Knowledge", a semantic web project that ran from 1999 to 2002. It contains a triplestore.Sesame...

 backends for actually storing and querying the RDF data.

Features

• Simple plugin design, with 5 different classes of plugins
• Server/client architecture which allows to run an RDF storage remotely. Interfaces for communication over TCP, Unix sockets, and D-Bus are provided
• Fully documented API using Doxygen
  Doxygen
  Doxygen is a documentation generator for multiple programming languages.Doxygen is a tool for writing software reference documentation. The documentation is written within code, and is thus relatively easy to keep up to date...
  
  
• CLucene
  Lucene
  Apache Lucene is a free/open source information retrieval software library, originally created in Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License....
  
  index which provides a full-text query index