lttoolbox is a toolbox for lexical processing, morphological analysis
and generation of words. The analysis is the process of splitting of
words splitting a word (e.g. cats) into its lemma 'cat' and the
grammatical information <n><pl>.  The generation is the opposite
process.
The package is split into three programs, lt-comp, the compiler,
lt-proc, the processor, and lt-expand, which generates all possible
mappings between surface forms and lexical forms in the dictionary.

WWW: http://wiki.apertium.org/wiki/Lttoolbox