Comprehensive list of Search Engines - The Search Engine List. Cuil. Lucene. Apache LuceneTM is a high-performance, full-featured text search engine library written entirely in Java. It is a technology suitable for nearly any application that requires full-text search, especially cross-platform. Apache Lucene is an open source project available for free download. Please use the links on the right to access Lucene. Lucene offers powerful features through a simple API: Scalable, High-Performance Indexing over 150GB/hour on modern hardwaresmall RAM requirements -- only 1MB heapincremental indexing as fast as batch indexingindex size roughly 20-30% the size of text indexed Powerful, Accurate and Efficient Search Algorithms Cross-Platform Solution Available as Open Source software under the Apache License which lets you use Lucene in both commercial and Open Source programs100%-pure JavaImplementations in other programming languages available that are index-compatible The Apache Software Foundation.
Sphinx | Open Source Search Server. Terrier IR Platform - Homepage. The Xapian Project.