Wolframalpha.com
Wolframalpha.com
http://www.wolframalpha.com
Description:
Unlike Google or a traditional search engine, Wolfram Alpha isn’t crawling the web and “scraping” information, a process where you try to extract data from a web page. Instead, it’s working with a variety of providers to gather public and private information. More important, it then uses a staff of over 150 people to ensure the information is clean and tagged in a way that Wolfram Alpha can present. For example, many government agencies publish statistical information. Wolfram Alpha obtains this data, which gets incorporated into the overall database people search against.


