Apache Lucene - Lucene Sandbox
Lucene project also contains a workspace, Lucene Sandbox, that is open to all Lucene committers, as well
as a few other developers. The purpose of the Sandbox is to host various third party contributions,
and to serve as a place to try out new ideas and prepare them for inclusion into the core Lucene
Users are free to experiment with the components developed in the Sandbox, but Sandbox components will not necessarily be maintained, particularly in their current state.
You can access the Lucene Sandbox repository at http://svn.apache.org/repos/asf/lucene/java/trunk/contrib/.
Snowball Stemmers for Lucene
This project provides pre-compiled versions of the Snowball stemmers for Lucene.
Background information on Snowball, which is a language for stemmers developed by Martin Porter.
Analyzers, Tokenizers, Filters
Contributed Analyzers, Tokenizers, and Filters for various languages.
The Ant project is a useful Ant task that creates a Lucene index out of an Ant fileset. It also contains an example HTML parser that uses JTidy.
The Lucene WordNet code consists of a single class which parses a prolog file from the WordNet site that contains a list of English words and synonyms. The class builds a Lucene index from the synonyms file. Your querying code could hit this index to build up a set of synonyms for the terms in the search query.
Lucli - Lucene Command-line Interface
The Lucli application allows index manipulation from the command-line.
A small set of classes for highlighting matching terms in search results.The repository for the Highlighter contribution.
High Frequency Terms
The miscellaneous package is for classes that don't fit anywhere else. The only class in it right now determines what terms occur the most inside a Lucene index. This could be useful for analyzing which terms may need to go into a custom stop word list for better search results.
RAM-based index that enables much faster searching than RAMDirectory.