Apache Lucene is a high-performance, fullfeatured text search engine library written entirely in Java
Apache Lucene is a free/open source information retrieval software library, originally created in Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License.
Lucene has been ported to other programming languages including PHP.
In Lucene, everything is a Document. A Lucene Document need notrefer to an actual file on a disk, it could also resemble a row in a
relational database.
Each developer is responsible for turning their own data sets intoLucene Documents. Lucene comes with a number of 3rd party
contributions, including examples for parsing structured data files suchas XML documents and Word files.