4store is an efficient, scalable, and stable RDF database. It was developed to underpin Semantic Web applications. It has been providing a base platform for these applications for around 3 years. It has successfully held and run queries over databases of 15GT, supporting a Web application used by hundreds of thousands of people.
The Cainteoir Engine is a library for reading and recording different document formats (ePub, HTML, MHT, RTF, email, and others) to various audio output formats (such as PulseAudio, WAV, and Ogg/Vorbis). It also provides the following command-line tools: cainteoir, a front-end to the Cainteoir text-to-speech library; metadata, which extracts metadata from documents to RDF tuples; and tagcloud, which generates tag clouds and tag cloud data.