Android has the largest installed base of all operating systems of any kind. Android has been the best
selling OS on tablets since 2013, and on smartphones it is dominant by any metric.
Initially developed by Android, Inc., which Google bought in 2005, Android was unveiled in 2007,
along with the founding of the Open Handset Alliance – a consortium of hardware, software, and
telecommunication companies devoted to advancing open standards for mobile devices. As of
July 2013, the Google Play store has had over one million Android applications ("apps") published,
and over 50 billion applications downloaded. An April–May 2013 survey of mobile application
developers found that 71% of developers create applications for Android,[19] and a 2015 survey
found that 40% of full-time professional developers see Android as their priority target platform,
which is comparable to Apple's iOS on 37% with both platforms far above others. At Google I/O
2014, the company revealed that there were over one billion active monthly Android users, up from
538 million in June 2013.
Android's source code is released by Google under open source licenses, although most Android
devices ultimately ship with a combination of open source and proprietary software, including
proprietary software required for accessing Google services. Android is popular with technology
companies that require a ready-made, low-cost and customizable operating system for high-tech
devices. Its open nature has encouraged a large community of developers and enthusiasts to use
the open-source code as a foundation for community-driven projects, which add new features for
advanced users or bring Android to devices originally shipped with other operating systems.