  ARKref is a tool for noun phrase coreference. It is a deterministic,
rule-based system that uses syntactic information from a constituent parser,
and semantic information from an entity recognition component. Its architecture
is based on the work of Haghighi and Klein (2009). ARKref was originally
written in 2009. At the time of writing, the last released version was in March
2011. This document describes that version, which is open-source and publicly
available at: http://www.ark.cs.cmu.edu/ARKref
