Apache Lucene

Apache Lucene(TM) is a high-performance, full-featured text
search engine library written entirely in Java. It is a
technology suitable for nearly any application that requires
full-text search, especially cross-platform.

The Apache Software Foundation

The Apache Software Foundation provides support for the
Apache community of open-source software projects. The
Apache projects are defined by collaborative consensus
based processes, an open, pragmatic software license
and a desire to create high quality software that leads the
way in its field. Apache Lucene, Apache Solr, Apache
Lucene.NET, Apache PyLucene, Apache Open Relevance
Project, Apache Lucy and Apache Droids and their
respective logos are trademarks of The Apache Software
Foundation. All other marks mentioned may be trademarks
or registered trademarks of their respective owners.