Common Resource Grep
Innovative text document search. http://dynaq.opendfki.de for details.
Powerful desktop search app for Windows, Linux and Mac
Lucene/Solr based search engine and workflow system
An open source search engine with RESTFul API and crawlers
extract unique file sets from sets with duplicates
First index images by contents, then search the index for similarities
zfind is a fast file search utility/API for searching within archives
Successor: <a href="http://syncarus.net">syncarus.net</a>
DuMP3 is a duplicate and similar file finder.