Another alternative for a search engine, with privacy along the lines of DuckDuckGo, is ixquick.com "the worlds most private search engine"
From http://en.wikipedia.org/wiki/Ixquick ...
"Ixquick returns the top ten results from multiple search engines. It uses a "Star System" to rank its results by awarding one star for every result that has been returned from a search engine. Thereby, the top search results are the ones that have been returned from the most search engines." "On July 7, 2009 Ixquick launched Startpage.com to offer a new service at a URL that is both easier to remember and spell. Startpage.com fetches its results straight from the Google search engine without saving the users' IP addresses or giving any personal user information to Google's servers" Surfboard Holdings B.V., the Dutch company that owns, ixquick and startpage, has released a beta testing version of StartMail - "the world's most private e-mail" https://startmail.com/ Official launch of paid StartMail accounts is projected to be in early 2014. I don't believe any of the above is open source. For an open source search engine you may want to take a look at... http://www.seeks-project.info/site/ cheers, Ian.