AllegroGraph is a closed source triplestore which is designed to store RDFtriples, a standard format for Linked Data.[1]
It also operates as a document store designed for storing, retrieving and managing document-oriented information, in JSON-LD format.
AllegroGraph is currently in use in commercial projects[2][3][4][5] and a US Department of Defense project.[6] It is also the storage component for the TwitLogic project[7] that is bringing the Semantic Web to Twitter data.[8]
Implementation
AllegroGraph was developed to meet W3C standards for the Resource Description Framework, so it is properly considered an RDF Database. It is a reference implementation for the SPARQL protocol.[9] SPARQL is a standard query language for linked data, serving the same purposes for RDF databases that SQL serves for relational databases.[10]
The first version of AllegroGraph was made available at the end of 2004.[12]
Languages
AllegroGraph has client interfaces for Java, Python, Ruby, Perl, C#, Clojure, and Common Lisp. The product is available for Windows, Linux, and Mac OS X platforms, supporting 32 or 64 bits.[13]
For query languages, besides SPARQL, AllegroGraph also supports Prolog and JavaScript.[14]