List of Search Engines - Open Source Search Engines

* DataparkSearch
* Egothor
* Gonzui
* Grub
* Ht://dig
* Isearch
* Lucene
* Lemur Toolkit & Indri Search Engine
* mnoGoSearch
* Namazu
* Nutch
* OpenFTS
* Sciencenet (for scientific knowledge, based on YaCy technology)
* Search Wikia
* Sphinx
* SWISH-E
* Terrier Search Engine
* Xapian
* YaCy
* Zettair