Lucene.Net.Analysis.Morfologik
This package provides dictionary-driven lemmatization ("accurate stemming") filter and analyzer for the Polish Language, driven by the Morfologik library developed by Dawid Weiss and Marcin Miłkowski.
For an introduction to Lucene's analysis API, see the Lucene.Net.Analysis package documentation.
The MorfologikFilter yields one or more terms for each token. Each of those terms is given the same position in the index.