Bing (search engine) web crawler. In early 1999, MSN Search launched a version which displayed listings from Looksmart blended with results from Inktomi except for a short time in 1999 when results from AltaVista were used instead. Since then Microsoft upgraded MSN Search to provide its own self-built search engine results, the index of which was updated weekly and sometimes daily. The upgrade started as a beta program in November 2004, and came out of beta in February 2005. Image search was powered by a third party, Picsearch. The service also started providing its search results to other search engine portals in an
Web search engine it gives back. While there may be millions of web pages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to rank the results to provide the "best" results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another. The methods also change over time as Internet usage changes and new techniques evolve. There are two main types of search engine that have evolved: one is a system