Android is a Linux-based operating system for mobile devices such as smartphones and tablet computers. It is developed by the Open Handset Alliance led by Google.[1][2] Google purchased the initial developer of the software, Android Inc., in 2005.[3] The unveiling of the Android distribution in 2007 was announced with the founding of the Open Handset Alliance, a consortium of 86 hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.[4][5][6][7] Google releases the Android code as open-source, under the Apache License.[8] The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android.[9] Android has a large community of developers writing applications apps that extend the functionality of the devices. Developers write primarily in a customized version of Java.[10] Apps can be downloaded from third-party sites or through online stores such as Android Market, the app store run by Google. As of October 2011 there were more than 400,000 apps available for Android, and the estimated number of applications downloaded from the Android Market as of December 2011 exceeded 10 billion.