Apache LuceneTM 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.
Apache Lucene is an open source project available for free download. Please use the links on the right to access Lucene.
Lucene offers powerful features through a simple API:
Scalable, High-Performance Indexing
over 150GB/hour on modern hardware
small RAM requirements -- only 1MB heap
incremental indexing as fast as batch indexing
index size roughly 20-30% the size of text indexed
Powerful, Accurate and Efficient Search Algorithms
ranked searching -- best results returned first
many powerful query types: phrase queries, wildcard queries, proximity queries, range queries and more
fielded searching (e.g. title, author, contents)
sorting by any field
multiple-index searching with merged results
allows simultaneous update and searching
flexible faceting, highlighting, joins and result grouping
fast, memory-efficient and typo-tolerant suggesters
pluggable ranking models, including the Vector Space Model and Okapi BM25
configurable storage engine (codecs)
Cross-Platform Solution
Available as Open Source software under the Apache License which lets you use Lucene in both commercial and Open Source programs
100%-pure Java
Implementations in other programming languages available that are index-compatible
United States
