A cross-platform, full-featured text search engine written entirely in Java. It can be configured as a standalone engine, metasearcher, peer-to-peer HUB or used as a class library. http://www.egothor.org/
Open source search engine tool released under GPL and designed to organize search within a website, group of websites, intranet or local system. http://www.dataparksearch.org/
Resources, ideas and news site for developing next generation open source search engines. Includes relevant source libraries and white papers. http://www.opensourcesearch.org/
Allows searching the KDE project CVS repository using GUISearch, a new kind of tool for finding code by looking at the applications' GUI text messages (e.g., "Undo") and returning associated callbacks/slots (e.g., slotUndo()). http://guisearch.sourceforge.net
Article that discusses the concepts of an open source, community-run, distributed web search service. One possible architecture is presented, although no working code or implementation exists. http://search.minty.org/