New version 1.1b, dated 31/Jan/2007. See link below.
As part of an ongoing research project in the discovery of low-frequency but important relationships in text files, (a development of chance discovery, I recently implemented the widely-used suffix stripping algorithm of Porter (1980) as a package available under the GPL.
The software can be downloaded from the link below.
I'm very grateful to Stephen Cox for completing my original implementation concerning treatment of the letter 'y' and fixing a defect. Stephen updated the code and shared much information on timings and an interesting implementation he has done using Stratego. His changes are incorporated in this release.