This program is supposed to parse MeSH into a Solr synonym file that maps each term in MeSH to all synonyms of its hyponyms (recursively).
The goal is to make Solr useful for cases where you want to search for all more specific instances of a more general term . For example, ideally you should be able to search for "Cancer" which then expands the query to all synonyms of "Cancer" in MeSH and all synonyms of all its hyponyms and, in turn, their hyponyms and so on (through the use of a SynonymFilter in Solr).
Testing of this program has been superficial at best so use with care.