Search engine optimization different signals. The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Some SEO practitioners have studied different approaches to search engine optimization, and have shared their personal opinions. Patents related to search engines can provide information to better understand search engines. In 2005, Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users. In 2007, Google announced a campaign against paid links that transfer PageRank. On June 15, 2009, Google disclosed that they had taken measures to mitigate the
Microsoft Entourage Spotlight search engine and AppleScript; however, the use of a monolithic database made it difficult to back up incrementally with Time Machine. Entourage also maintained a separate address book, but allowed synchronization of contacts and calendar events through Sync Services. Unlike the other applications in the Mac version of the Microsoft Office suite, Entourage did not share a name with its Microsoft Windows counterpart. Microsoft claimed that Entourage was intended "to address an entirely different audience". Entourage had its origins in Outlook Express 5 on the Mac, as well as Claris Emailer and contained "no ported code, and no Office