Siri /ˈsɪri/ is an intelligent personal assistant (Intelligent Software Assistant) and knowledge navigator which works as an application for Apple Inc.'s IOS. The application uses a Natural Language (Voice Recognition) user interface to answer questions, make recommendations, and perform actions by delegating requests to a set of Web services. Apple claims that the software adapts to the user's individual preferences over time and personalizes results. Siri was originally introduced as an iOS application available in the App Store by Siri, Inc., which was acquired by Apple on April 28, 2010. Siri, Inc. had announced that their software would be available for Blackberry and for phones running Android, but all development efforts for non-Apple platforms were cancelled after the acquisition by Apple. Siri has been an integral part of iOS since iOS 5 and was introduced as a feature of the iPhone 4S. Siri was added to the iPad (third generation) with the release of iOS 6, and has been included on all iOS devices since Fall 2012 http://en.wikipedia.org/wiki/Siri_(software)
Runs on ApacheMesos.