Solr

Solr is an open source enterprise search server based on the Lucene Java search library, with XML/HTTP and JSON APIs, hit highlighting, faceted search, caching, replication, and a web administration interface. It runs in a Java servlet container such as Tomcat.

• Nutch - an open-source web search engine
• Apache Lucene
• Red-Piranha
• XQEngine - a full-text search engine for XML
• MG4J - Managing Gigabytes for
• Zilverline Search Engine
• BDDBot - a web robot
• Egothor - a text search engine
• Oxyus - an open source search engine
• Aperture - a Java framework for getting data and metadata
• JXTA
• YaCy: P2P Web Search Engine