Duck Duck Go
This search engine is a great option if you value your privacy above all else. The team behind DuckDuckGo believes in better search functions without tracking its users. Its features include “goodies” (special search queries such as calculations and programming), browser extensions and perhaps most of all, peace of mind.
Wolfram|Alpha
Instead of searching the web for answers to your questions, Wolfram|Alpha conducts dynamic computations based on built-in data, algorithms and other methods. The search engine's goal is to build on existing knowledge and become a single, reliable source for definitive answers.
Ark
When Facebook doesn't cut it for finding people, Ark comes in handy. As an alternative to Graph Search, you can search through more than 1 billion people based on filters such as location, college and employment. If you just moved to a new city, Ark comes in handy to find others with similar interests.
Blekko
Blekko's slogan is “the spam-free search engine,” and its mission is to combine traditional algorithms with user knowledge and partner expertise in order to deliver results from the most reputable sites. Blekko has an “editorial” approach — it wants you to feel like your search results are handpicked for what you're looking for online.
GoodSearch
GoodSearch donates 50% of revenues to charities and schools that its users choose. Additional features include GoodShop, a catalog of merchants that help support causes; GoodDining, a year-round “dine out for charity” program; and most recently, GoodSurvey, which lets people take market research surveys to earn money for their favorite causes. GoodSearch is powered by Yahoo and has 510,000 unique monthly visitors.
YaCy
YaCy focuses on decentralized web search. This means that the engine allows you to search the entire public Internet through a worldwide peer network, in which everyone's information is equal and content is never censored. YaCy is free and can be downloaded from the website.
Apache Solr
Similar to YaCy, Apache Solr is an open-source, standalone search server. Developed from the Apache Lucene project, Solr's features include full text search, faceted search (using multiple filters), clustering information based on categories, rich document (DOC and PDF) handling and near real-time indexing.
Dogpile
InfoSpace (now Blucora) created Dogpile to save users time. The search engine uses powered metasearch technology through Google, Yahoo and Yandex. Since these three search engines have their own ways of finding information, Dogpile looks at all of them and delivers results that are most relevant to your search.
Ixquick
Ixquick is another great choice for users looking for privacy and powerful search. Ixquick doesn't collect or share any information, and it awards results with stars for every search engine that “agrees” on it. For example, a search result with five stars means that five search engines agree on it, increasing accuracy. You can enter any advanced search, and Ixquick will send the query to the search engines that can handle that specific query.
