Joshua logo (picture of a Joshua tree)

Joshua Machine Translation Toolkit

Stable version: 5.0 (Released 16 August 2013)


Joshua is an open-source statistical machine translation decoder for hierarchical and syntax-based machine translation, written in Java. It is developed as a research collaboration between the Human Language Technology Center of Excellence at Johns Hopkins University and Chris Callison-Burch's research group at the University of Pennsylvania.

The latest version of Joshua is version 5.0. Its changes are described in the paper

Joshua 5.0: Sparser, better, faster, server BibTeX
Matt Post, Juri Ganitkevitch, Luke Orland, Jonathan Weese, Yuan Cao, and Chris Callison-Burch
WMT 2013. Sofia, Bulgaria. August.

You might also be interested in older papers describing Joshua 1.0, the Joshua demo paper, 2.0, 3.0, and 4.0.

Technical Support

Support is provided in two forms: Technical support for end-users of Joshua, and Developer support for contributors.


Joshua was originally ported from David Chiang's Python implementation of Hiero by Zhifei Li. Since then, there have been a number of contributors to the project (listed here in alphabetical order).

Please email if you know of anyone who has been left off this list.


We gratefully acknowledge support provided by the following institutions.
Human Language Technology Center of Excellence logo