Hulbee Enterprise Search - Hulbee Enterprise Search is another powerful site search solution that intelligently retrieves information and documents regardless of their source or location.
Apache Solr - Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and...
SearchSpring - SearchSpring is an eCommerce site search tool.
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
SearchBlox - SearchBlox is an out-of-the-box Enterprise Search Solution built on top of Apache Lucene/Solr.
Coveo - Enterprise search technology for better customer support, customer self-service, and knowledge management in the digital workplace.