To develop a flexible Open Source platform for constructing spoken command grammars.

The Regulus project has the following main objectives:

• Open Source
  Material is freely available under the Open Source LGPL license.
  
• Example-Based Construction
  All application-specific command grammars are derived from a single general grammar, using example-based methods driven by small corpora of examples.
  
• High Performance Recognition
  Performance of grammars built using Regulus should not be inferior to that of hand-coded grammars.
• Scalability
  The methods should scale well as the general grammar is extended, and as the example corpora are made larger.
  
• Documentation
  The software should be adequately documented.

The Open Source Regulus platform has been developed since 2001 by a consortium whose main partners have been NASA Ames, the University of Geneva, and Fluency Voice Technology. The central idea is to develop a single English grammar, based on general linguistic principles, from which one can derive application-specific command grammars using example-based methods. Software available from the Open Source site includes the general grammar, compilation tools, an integrated development environment, documentation and examples. The tools are implemented in SICStus Prolog, and produce grammars compatible with the Nuance speech recognition toolkit.

Experiments described in our tutorial presentation at the ACL 2004 conference show that the Regulus compilation process scales well both with respect to the size of the general grammar and the size of the example corpus, and produces grammars very competitive with hand-coded versions.

Regulus has been used to build command grammars for Clarissa and several other major projects, including a medical speech translator and a speech enabled home control system.

Mar 2001:    First version of Regulus.
Apr 2003:    Open Source system available on SourceForge.
Jul 2004:      Regulus tutorial at ACL conference, Barcelona, Spain.