A new kid on the block when it comes to open source enterprise search. The company must still provide some evidence of a real open source strategy: frequent release of open source code & strong community would be appreciated.

Sphinx is a full-text search engine, distributed under GPL version 2. Commercial license is also available for embedded use.

Dieselpoint Search™ is search and navigation software for enterprise data including document collections, databases, and XML.

Endeca Information Access Platform is one of the leading enterprise search solution. With a strong bias on data analytics, it can be see as a new way to address business intelligence.

At the heart of Autonomy's infrastructure software lies the Intelligent Data Operating Layer (IDOL) Server. The IDOL Server collects indexed data from connectors and stores it in its proprietary structure, optimized for fast processing and retrieval of data. As the information processing layer, IDOL forms a conceptual and contextual understanding of all content in an enterprise, automatically analyzing any piece of information from over 1,000 different content formats and even people's interests. Over 500 operations can be performed on digital content by IDOL, including hyperlinking, agents, summarization, taxonomy generation, clustering, eduction, profiling, alerting and retrieval.