The RASP System

System Overview

RASP is a domain-independent, robust parsing system for English. It is freely available to download for academic (non-commercial) applications under the GNU Lesser General Public License. It is distributed as source code, and has been developed and tested on widely used Unix architectures (Intel-32bit and -64bit Linux and macOS). An "industrial-strength" version with auxiliary tools, XML functionality, Unicode handling etc is available under a commercial licence agreement through the company iLexIR.

The development of RASP was partially funded by EU and UK research projects and fellowships, most notably the EPSRC-funded project Robust Accurate Statistical Parsing (RASP). Since the end of that project, RASP has continued to be extended and enhanced on an on-going basis, both as part of academic projects and also by its commercial licensor, iLexIR.

An informal description of the RASP system is online, with examples of system output. The first public release of the system was in January 2002; the second release (RASPv2) was available only via a licensing process; the third release of RASP is now available for download, under the GNU Lesser General Public License (LGPL).

Note that at present the system does not run on Microsoft Windows.


March 2018: version 3.2 of RASP is available to download via iLexIR.

September 2012: version 3.1 of RASP has been released and can be downloaded from the iLexIR web site.

March 2011: the third release of RASP has been released, under an open source license.

January 2009: the parser binary for 32-bit Linux in the second release of RASP has started to give the error message

Lisp has expired. Please contact for a new license file.
We have a (slightly unsatisfactory) fix for this problem, and we are working urgently on a new release. Until then, please run RASP on a different architecture; if this is not possible then

This new version of the parser binary prints some diagnostic messages on startup and may give slightly different parse results to the other binaries; we hope this does not cause problems.

Spring 2007: if you are running the second release of RASP on a Linux system based on Fedora Core 6 and get the error message

tag/ix86_linux/label: error while loading shared libraries:
cannot open shared object file: No such file or directory
then edit the file scripts/ to replace

Autumn 2006: we hope to add binaries for Mac OSX on PowerPC and Intel soon.

June 2006: second public release. If you are a current user of RASP we will be notifying you by email about the new release.

Summer 2004: if you are running the first release of RASP on a recently upgraded Linux system and see the following error message

gde/ix86_linux/ symbol errno, version GLIBC_2.0 not
defined in file with link time reference
then please download the second release.

January 2002: the first public release of the parsing toolkit is now available.

Referencing Use of RASP

If you use RASP and publish any results derived from it, we ask that you cite the following paper:

Briscoe, E., J. Carroll and R. Watson (2006) The Second Release of the RASP System. In Proceedings of the COLING/ACL 2006 Interactive Presentation Sessions, Sydney, Australia. 77-80.

Other relevant publications

Rei, M. and E. Briscoe (2013) Parser lexicalisation through self-learning. In Proceedings of NAACL-HLT 2013, Atlanta, Georgia. 391-400.

Andersen, O., J. Nioche, E. Briscoe and J. Carroll (2008) The BNC parsed with RASP4UIMA. In Proceedings of the Sixth Language Resources and Evaluation Conference (LREC), Marrakech, Morocco. 865-869.

Briscoe, E. and J. Carroll (2006) Evaluating the accuracy of an unlexicalized statistical parser on the PARC DepBank. In Proceedings of the COLING/ACL 2006 Main Conference Poster Sessions, Sydney, Australia. 41-48.

Watson, R., J. Carroll and E. Briscoe (2005) Efficient extraction of grammatical relations. In Proceedings of the 9th International Workshop on Parsing Technologies, Vancouver, Canada. 160-170.