Code

Lucene-SKOS: An analyzer module for Apache Lucene 4.x and Solr 4.x, which takes existing SKOS concepts schemes and performs term expansion for given Lucene documents and/or queries.

Lucene-Relevance: Lucene 4.x implementations of good retrieval functions.
LtcSimilarity: TF-IDF (ltc); BM25Similarity: default BM25 setting, BM25L and BM25+