This is a list of free information retrieval libraries, which are

libraries A library is a collection of materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or digital access (soft copies) materials, and may be a physical location or a vir ...

used in

software development Software development is the process of conceiving, specifying, designing, programming, documenting, testing, and bug fixing involved in creating and maintaining applications, frameworks, or other software components. Software development inv ...

for performing it retrieval functions. It is not a complete list of such libraries, but is instead a list of free information retrieval libraries with articles on Wikipedia. It does not include commercial software libraries.

Libraries for searching and indexing

Lemur Lemurs ( ) (from Latin ''lemures'' – ghosts or spirits) are wet-nosed primates of the superfamily Lemuroidea (), divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madaga ...

Lucene Apache Lucene is a free and open-source search engine software library, originally written in Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License. Lucene is widely used as ...

Solr Solr (pronounced "solar") is an open-source enterprise-search platform, written in Java. Its major features include full-text search, hit highlighting, faceted search, real-time indexing, dynamic clustering, database integration, NoSQL features a ...

Elasticsearch Elasticsearch is a search engine based on the Lucene library. It provides a distributed, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents. Elasticsearch is developed in Java and is dual ...

Manatee Manatees (family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living speci ...

Sphinx A sphinx ( , grc, σφίγξ , Boeotian: , plural sphinxes or sphinges) is a mythical creature with the head of a human, the body of a lion, and the wings of a falcon. In Greek tradition, the sphinx has the head of a woman, the haunches o ...

* Terrier Search Engine *

Xapian Xapian is a free and open-source probabilistic information retrieval library, released under the GNU General Public License (GPL). It is a full-text search engine library for programmers. It is written in C++, with bindings to allow use from P ...

{{DEFAULTSORT:Information retrieval libraries Lists of software