Solr is an open source NoSQL enterprise search platform built on Apache Lucene. Supporting distributed search and index replication, Solr is highly reliable, scalable and fault tolerant. It runs as a standalone full-text search server with a REST-like API and provides features including hit highlighting, faceted search, near real-time indexing, dynamic clustering, database integration, and geospatial search. Currently, Solr powers some of the highest-traffic websites and applications in the world.
In 2004, CNET Networks, an American media website, started Solr to support search capability and later donated to Apache Software Foundation as a open-source project in 2006. In 2007, graduated as a top-level project (TLP), Solr grew steadily with more features and supported several popular websites. Finally in 2010, Solr was merged with Lucene as a sub project and changed the version number to 3.1 after Solr 1.4 to match that of Lucene.
Apache Software Foundation