Android (operating system)

Android is a software stack for mobile devices that includes an operating system, middleware and key applications. Google Inc. purchased the initial developer of the software, Android Inc., in 2005. Android's mobile operating system is based on the Linux kernel. Google and other members of the Open Handset Alliance collaborated on Android's development and release. The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android. Android was listed as the best-selling Smartphone platform world-wide in Q4 2010 by Canalys.

Android has a large community of developers writing applications ("apps") that extend the functionality of the devices. There are currently more than 250,000 apps available for Android. Android Market is the online app store run by Google, though apps can also be downloaded from third-party sites. Developers write primarily in the Java language, controlling the device via Google-developed Java libraries.

The unveiling of the Android distribution on 5 November 2007 was announced with the founding of the Open Handset Alliance, a consortium of 80 hardware, software, and telecom companies devoted to advancing open standards for mobile devices.Google released most of the Android code under the Apache License, a free software and open source license.

The Android open-source software stack consists of Java applications running on a Java-based, object-oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, and Bionic libc.

Version history

The version history of the Android operating system began with the release of version 1.0 in September 2008. Android is a mobile operating system developed by Google and the Open Handset Alliance. Android has seen a number of updates since its original release. These updates to the base operating system typically fix bugs and add new features. Generally, each version is developed under a code name based on a dessert item. The code names are in alphabetical order (Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, and the future version, Ice Cream Sandwich).

Android has seen a number of updates since its original release. These updates to the base operating system typically fix bugs and add new features. Generally, each new version of the Android operating system is developed under a code name based on a dessert item. Past updates included Cupcake and Donut. The code names are in alphabetical order (Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, and the upcoming Ice Cream Sandwich). Below is a list of the most recent versions, and what they include:

2.0 (Eclair) included a new web browser, with a new user interface and support for HTML5 and the W3C Geolocation API. It also included an enhanced camera app with features like digital zoom, flash, color effects, and more.

2.1 (Eclair) included support for voice controls throughout the entire OS. It also included a new launcher, with 5 homescreens instead of 3, animated backgrounds, and a button to open the menu (instead of a slider). It also included a new weather app, and improved functionality in the Email and Phonebook apps.

2.2 (Froyo) introduced speed improvements with JIT optimization and the Chrome V8 JavaScript engine, and added Wi-Fi hotspot tethering and Adobe Flash support

2.3 (Gingerbread) refined the user interface, improved the soft keyboard and copy/paste features, and added support for Near Field Communication

3.0 (Honeycomb) was a tablet-oriented release which supports larger screen devices and introduces many new user interface features, and supports multicore processors and hardware acceleration for graphics.The Honeycomb SDK has been released and the first device featuring this version, the Motorola Xoom tablet, went on sale in February 2011.
3.1 (Honeycomb) was announced at the 2011 Google I/O on 10 May 2011.

3.2 (Honeycomb) is "an incremental release that adds several new capabilities for users and developers." Highlights include optimization for a broader range of screen sizes; new "zoom-to-fill" screen compatibility mode; capability to load media files directly from the SD card; and an extended screen support API, providing developers with more precise control over the UI.

Below is a list of future releases that have been announced:

4.0 (Ice Cream Sandwich) is said to be a combination of Gingerbread and Honeycomb into a "cohesive whole." It will be released in Q4 2011