Nutch is open source web-search software. It builds on Lucene Java, adding web-specifics, such as a crawler, a link-graph database, parsers for HTML and other document formats, etc.
MozDex is a search engine seeded from the dmoz.org directory. MozDex uses open source search technologies to create an open and fair index. Our goal is to be able to provide a powerful and open search service to the community. Mozdex is built around the Nutch Search technology.