Apache Lucene is a free/open source information retrieval software library, originally created in Java. It is supported by the Apache Software Foundation and is released under the Apache Software License.
Lucene is a Java library that adds text indexing and searching capabilities to an application. It is not a complete application that one can just download, install, and run. It offers a simple, yet powerful core API.
Lucene offers two main services: text indexing and text searching. These two activities are relatively independent of each other, although indexing naturally affects searching.
Lucene has been widely recognized for its utility in the implementation of Internet search engines and local, single-site searching.
Lucene itself is just an indexing and search library,
- The Apache project Nutch offers crawling and HTML parsing functionality,
- The Apache project Solr is a fully-featured search server based on Lucene,
- Compass is a Java Search Engine Framework built on the top of Lucene,
- Liferay, the PANGAEA data library, and the EB-eye search engine (which specialises in biological information) are also based on Lucene.
