Bing (known previously as Live Search, Windows Live Search, and MSN Search) is a web search engine (advertised as a "decision engine") from Microsoft.Bing was unveiled by Microsoft CEO Steve Ballmer on May 28, 2009, at the All Things Digital conference in San Diego, California, for release on June 1, 2009. Notable changes include the listing of search suggestions while queries are entered and a list of related searches (called "Explore pane") based on semantic technology from Powerset, which Microsoft purchased in 2008.On July 29, 2009, Microsoft and Yahoo! announced a deal in which Bing would power Yahoo! Search. All Yahoo! Search global customers and partners were expected to have made the transition by early 2012.In October 2011, Microsoft stated that they were working on new back-end search infrastructure with the goal of delivering faster and slightly more relevant search results for users. Known as "Tiger", the new index-serving technology has been incorporated into Bing globally since August 2011. In May 2012, Microsoft announced another redesign of its search engine that includes "Sidebar", a social feature that searches users' social networks for information relevant to the search query. In September 2013, a new-look Bing was released to tie in with Microsoft's "Metro" design language.