Google, Yahoo, MSN what's the difference?

X-Ranks: The shaping battle of quality methodologies: "It's been a long time coming but a picture is beginning to emerge of how the Big Four search engines really differ from each other in terms of ranking algorithms. Yahoo! remains the most secretive of the engines. Google's increasingly complex algorithm is the best documented, though least well-understood. When Yahoo! brought out its own search engine (April 2003), it supposedly combined the best features of Altavista, AllTheWeb, and Inktomi's technologies. Inktomi was the first major search engine to place significance on linkage. Inktomi relied on true, unweighted link popularity. Altavista's chief strength, in my opinion, lay in its ability to..."