University of Southampton, England.
Description of declarative query language for manipulating RDF files for use in the symantic Web.
Short, very clear explanations.
Gives easy way to describe lists, maps, trees of typed data in small, easily read form. Simple, intuitive API lets one read, write, access all data structures via one class. Descriptions, documents, FAQ, mail list, downloads. [Open Source]
Growing article, with links to many related topics. [Wikipedia]