Lucene.net

Lucene.net

Apache Lucene™ is a high-performance, full-featured text search engine library written in Java which makes it easy to add search functionality to an application or website. It does so by adding content to a full-text index. It then allows you to perform queries on this index, returning results ranked by either the relevance to the query or sorted by an arbitrary field such as a document's last modified date.

Solr

Solr

Apache Solr is a web application built around Apache Lucene search engine with features such as faceted search and filtering, geospatial search, fast incremental updates and index replication. Solr enables powerful matching capabilities including phrases, wildcards, joins, grouping and much more across any data type.

Endeca

Endeca

Endeca is a search and business intelligence software company that helps people both find what they need and understand what they found. Endeca enables IT organizations to rapidly deliver innovative, interactive solutions for the most demanding decision-making environments in the world, including large global enterprises, online businesses, and government agencies dealing with enormous volumes of sensitive information.

EasyAsk

EasyAsk

EasyAsk is the e-commerce industry’s most intuitive site search, navigation and merchandising software.  It is s an easy-to-use, powerful site search, navigation, and merchandising software solution that helps B2C and B2B companies boost revenue opportunities, increase customer loyalty, and strengthen relationships with customers.