Apache Lucene

Apache Lucene is a high-performance, full-featured search engine library developed in Java, designed for applications requiring structured and full-text search capabilities. It serves as the core search component for both Apache Solr and Elasticsearch, and is utilized in applications ranging from mobile devices to large-scale websites like Twitter and Wikipedia. Lucene's architecture is optimized for scalability, speed in indexing, and efficiency in search operations.

Key functionalities of Lucene include advanced analysis, tokenization, spellchecking, and hit highlighting. It supports a variety of search algorithms, including ranked searching and multiple query types, equipped with flexible faceting and ranking models. Additionally, Lucene is cross-platform compatible, ensuring that it can be integrated into various environments. It is distributed under the Apache Software License, making it suitable for both commercial and open-source applications.

For those looking to integrate or utilize Lucene, comprehensive documentation is available, as well as resources for downloading the library and accessing community support.