Sesame is an Open Source RDF Schema-based repository and querying facility. It is a scalable, modular architecture for persistent storage and querying of RDF and RDF Schema. It supports two query languages (SPARQL and SeRQL), and can use main memory or PostgreSQL, MySQL and Oracle 9i databases for storage.
Soprano (formerly known as QRDF) is a library that provides a highly usable object-oriented C++/Qt4 framework for RDF data. It uses different RDF storage solutions as backends through a simple plugin system. Soprano is targetted at desktop applications that need a RDF data storage solution. It has been optimized for easy usage and simplicity.
Nx2 is a somewhat complex Web application that acts as a frontend to music databases. Based on XUL, it runs in Gecko based browsers such as Firefox. Built on this idea is a client/server model where several Nx2 frontends can connect to each other, creating a way to link together databases on different networks.
ASTRA is a set of software tools for mediated interpersonal awareness, addressing the need to stay in touch with family and friends or the need to be reassured regarding their well-being. The software provides a service oriented architecture, user tools, and applications that support communities to appropriate Pervasive Awareness applications.
Graffiti is an RDF store based on dynamic translation of RDF queries into SQL. It allows you to map any relational database schema into RDF semantics and vice-versa, and to store any RDF data in a relational database. Since 2003, this RDF store was used as the primary means of data access in the Samizdat open publishing engine, and now it's released as a stand-alone module ready for use in other applications.
FDRDF is a tool that builds a catalogue of descriptions in an RDF representation of the specified files. The descriptions currently include: file status (as per the stat system call); SHA-1 hash over the file contents; MIME type (as guessed by the file tool), geospatial metadata (as per GDAL), and GRIB file composition (as per GRIB API).