TinySPARQL
TinySPARQL is a file indexing and search framework for Linux and other Unix-like systems. It is written in the C programming language.
TinySPARQL has been adopted by the GNOME desktop environment and is heavily integrated into GNOME Shell and GNOME Files.
At its core, TinySPARQL is a general-purpose SPARQL-based database; although it is developed together with the file indexer component, it may be used to store or access any kind of data that follows the RDF data model.