Obtaining a licence for the CLAWS tagger

CLAWS POS tagger | Free CLAWS WWW trial service | Tagging service

Academic licence (Unix, Linux, OSX or Windows)

A site licence for academic institutions for CLAWS4 may be purchased from UCREL for a fee of £750 + VAT (as appropriate). This fee includes introductory assistance and an information pack which contains program details, relevant papers, a reference list and tag set examples. The site licence is available for Unix variants (Solaris, Linux or MacOSX) or Windows versions. Note that we have tested WinCLAWS on computers running Windows XP. Academic single user licences are also available for CLAWS4 for £100 + VAT (as appropriate). Multiple licence copies (for up to 20 users) can also be purchased for £350 + VAT (as appropriate). The UNIX installation requires approximately 6Mb of disk space. All of these options can be purchased online via the Lancaster University online store.

Commercial licence, consultancy or training

Prices for commercial licences are available on request. If you require additional assistance please contact us with your specific needs.


On a MacBook (4Gb RAM 2.4 GHz Intel Core 2 Duo), CLAWS takes around 12 minutes to tag one million words. On a DELL PE 2950 III (Quad Core Xeon X5450, 3.0GHz, 2x6MB, 1333MHz FSB, 24Gb RAM), CLAWS takes approximately 8 minutes to tag one million words. For older machines, e.g. on a Sun Ultra 10 300Mhz UltraSPARC IIi 512Mb RAM running Solaris 7, CLAWS takes about 15 minutes to tag 250,000 words. The same task takes about 75 minutes on a Sun SPARC20 model 61 256Mb RAM running SunOS4.1.3, 120 minutes on a Sun SPARC10, 210 minutes on a Sun SPARC2, and 240 minutes on a Sun SPARC classic all running Sun OS4.1.X.

Contact details

Initial enquiries should be made to Paul Rayson, Director of UCREL.

Instead of obtaining a licence for the CLAWS software, you may prefer to make use of our CLAWS tagging service.