Web search engine launched on June 1, 2009. On July 29, 2009, Yahoo! and Microsoft finalized a deal in which Yahoo! Search would be powered by Microsoft Bing technology. A search engine maintains the following processes in near real time: Web search engines get their information by web crawling from site to site. The "spider" checks for the standard filename "robots.txt", addressed to it, before sending certain information back to be indexed depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, as evidenced by the standard HTML markup of the informational content, or its metadata in
Microsoft Search Server to extract the text of the file for full text indexing as well. The handlers and iFilters MSS uses are the same as used by SharePoint, Microsoft SQL Server and Windows Search as well. The data sources that are to be indexed are identified by their URIs and have to be configured prior to indexing. The indexer updates the search index as soon as an item is indexed ("continuous propagation") so that the items can be queried against even before the indexing crawl is complete. MSS can also federate searches to other search services (including SharePoint and web search servers)