The version history of the Androidmobile operating system began with the release of the Android beta in November 2007. The first commercial version, Android 1.0, was released in September 2008. Android is under ongoing development by Google and the Open Handset Alliance (OHA), and has seen a number of updates to its base operating system since its initial release.
Since April 2009, Android versions have been developed under a codename and released according to alphabetical order: Cupcake (1.5), Donut (1.6), Eclair (2.0–2.1), Froyo (2.2–2.2.3), Gingerbread (2.3–2.3.7), Honeycomb (3.0–3.2.6), Ice Cream Sandwich (4.0–4.0.4), Jelly Bean (4.1–4.3), and KitKat (4.4). On 3 September 2013, Google announced that 1 billion activated devices now use the Android OS worldwide. The most recent major Android update was KitKat 4.4, which was released to commercial devices on 22 November 2013, via an OTA update.
There were at least two internal releases inside Google and the OHA before the Android beta was released in November 2007. For internal milestone in internal releases, names of fictional robots were chosen, with various releases code-named "Astro Boy", "Bender" and "R2-D2". Dan Morrill created some of the first mascot logos, but the current green Android logo was designed by Irina Blok. The project manager, Ryan Gibson, conceived of the confections naming scheme that has been used for the majority of the public releases, starting with Android 1.5.
The Android beta was released on 5 November 2007, while the software development kit (SDK) was released on 12 November 2007. The 5 November date is popularly celebrated as Android's "birthday". Public beta versions of the SDK were released in the following order:
Android 1.0, the first commercial version of the software, was released on 23 September 2008. The first commercially available Android device was the HTC Dream. Android 1.0 incorporated the following features:
23 September 2008
Android Market application download and updates through the Market application
On 9 February 2009, the Android 1.1 update was released, initially for the HTC Dream only. Android 1.1 was known as "Petit Four" internally, though this name was not used officially. The update resolved bugs, changed the Android API and added a number of features:
9 February 2009
Details and reviews available when a user searches for businesses on Maps
Longer in-call screen timeout default when using the speakerphone, plus ability to show/hide dialpad
On 27 April 2009, the Android 1.5 update was released, based on Linux kernel 2.6.27. This was the first release to officially use a codename based on a dessert item ("Cupcake"), a theme which would be used for all releases henceforth. The update included several new features and UI amendments:
30 April 2009
Support for third-party virtual keyboards with text prediction and user dictionary for custom words
Support for Widgets – miniature application views that can be embedded in other applications (such as the Home screen) and receive periodic updates
Video recording and playback in MPEG-4 and 3GP formats
Auto-pairing and stereo support for Bluetooth (A2DP and AVRCP profiles)
Copy and paste features in web browser
User pictures shown for Favorites in Contacts
Specific date/time stamp shown for events in call log, and one-touch access to a contact card from call log event
Open Accessory Library support. Open Accessory was introduced in 3.1 (Honeycomb) but the Open Accessory Library grants 2.3.4 added support when connecting to a USB peripheral with compatible software and a compatible application on the device
Switched the default encryption for SSL from AES256-SHA to RC4-MD5.
On 22 February 2011, the Android 3.0 (Honeycomb) SDK – the first tablet-only Android update – was released, based on Linux kernel 2.6.36. The first device featuring this version, the Motorola Xoom tablet, was released on 24 February 2011. The update's features included:
22 February 2011
Optimized tablet support with a new “holographic” user interface
Added System Bar, featuring quick access to notifications, status, and soft navigation buttons, available at the bottom of the screen
Added Action Bar, giving access to contextual options, navigation, widgets, or other types of content at the top of the screen
Simplified multitasking – tapping Recent Applications in the System Bar allows users to see snapshots of the tasks underway and quickly jump from one application to another
Redesigned keyboard, making typing fast, efficient and accurate on larger screen sizes
Simplified, more intuitive copy/paste interface
Multiple browser tabs replacing browser windows, plus form auto-fill and a new “incognito” mode allowing anonymous browsing
Quick access to camera exposure, focus, flash, zoom, front-facing camera, time-lapse, and other camera features
Ability to view albums and other collections in full-screen mode in Gallery, with easy access to thumbnails for other photos
New two-pane Contacts UI and Fast Scroll to let users easily organize and locate contacts
New two-pane Email UI to make viewing and organizing messages more efficient, allowing users to select one or more messages
The SDK for Android 4.0.1 (Ice Cream Sandwich), based on Linux kernel 3.0.1, was publicly released on 19 October 2011. Google's Gabe Cohen stated that Android 4.0 was "theoretically compatible" with any Android 2.3.x device in production at that time. The source code for Android 4.0 became available on 14 November 2011. Ice Cream Sandwich was the last version to officially support Adobe Systems' Flash player. The update introduced numerous new features:
19 October 2011
Major refinements to the "Holo" interface with new Roboto font family
Soft buttons from Android 3.x are now available for use on phones
Separation of widgets in a new tab, listed in a similar manner to applications
Easier-to-create folders, with a drag-and-drop style
A customizable launcher
Improved visual voicemail with the ability to speed up or slow down voicemail messages
Pinch-to-zoom functionality in the calendar
Integrated screenshot capture (accomplished by holding down the Power and Volume-Down buttons)
Improved error correction on the keyboard
Ability to access applications directly from lock screen
Improved copy and paste functionality
Better voice integration and continuous, real-time speech to text dictation
Face Unlock, a feature that allows users to unlock handsets using facial recognition software
Automatic syncing of browser with users' Chrome bookmarks
Data Usage section in settings that lets users set warnings when they approach a certain usage limit, and disable data use when the limit is exceeded
Ability to shut down applications that are using data in the background
Improved camera application with zero shutter lag, time lapse settings, panorama mode, and the ability to zoom while recording
Built-in photo editor
New gallery layout, organized by location and person
Refreshed "People" application with social network integration, status updates and hi-res images
Android Beam, a near-field communication feature allowing the rapid short-range exchange of web bookmarks, contact info, directions, YouTube videos and other data
Fixed minor bugs on the Verizon Galaxy Nexus, the US launch of which was later delayed until December 2011
(For Canadian consumers, 4.0.2 reportedly created a bug on the Galaxy Nexus that crashed the application market when users attempted to view details of any Android application. It also inadvertently reduced the NFC capabilities of the Nexus phone.)
Google announced Android 4.1 (Jelly Bean) at the Google I/O conference on 27 June 2012. Based on Linux kernel 3.0.31, Jelly Bean was an incremental update with the primary aim of improving the functionality and performance of the user interface. The performance improvement involved "Project Butter", which uses touch anticipation, triple buffering, extended vsync timing and a fixed frame rate of 60 fps to create a fluid and "buttery-smooth" UI. Android 4.1 Jelly Bean was released to the Android Open Source Project on 9 July 2012, and the Nexus 7 tablet, the first device to run Jelly Bean, was released on 13 July 2012.
9 July 2012
Smoother user interface:
Vsync timing across all drawing and animation done by the Android framework, including application rendering, touch events, screen composition and display refresh
Google was expected to announce Jelly Bean 4.2 at an event in New York City on 29 October 2012, but the event was cancelled due to Hurricane Sandy. Instead of rescheduling the live event, Google announced the new version with a press release, under the slogan "A new flavor of Jelly Bean". Jelly Bean 4.2 was based on Linux kernel 3.4.0, and debuted on Google's Nexus 4 and Nexus 10, which were released on 13 November 2012.
Accessibility improvements: triple-tap to magnify the entire screen, pan and zoom with two fingers. Speech output and Gesture Mode navigation for blind users
New clock application with built-in world clock, stop watch and timer
All devices now use the same interface layout, previously adapted from phones on 4.1 for smaller tablets (with centered software buttons, the system bar at the top of the screen, and a home screen with a dock and centered application menu), regardless of screen size
Increased number of extended notifications and Actionable Notifications for more applications, allowing users to respond to certain notifications within the notification bar and without launching the application directly
Google released Jelly Bean 4.3 under the slogan "An even sweeter Jelly Bean" on 24 July 2013 during an event in San Francisco called "Breakfast with Sundar Pichai". Most Nexus devices received the update within a week, although the 2nd generation Nexus 7 tablet was the first device to officially ship with it. A minor bugfixing update was released on 22 August 2013.
Google announced Android 4.4 KitKat, internally known as Project Svelte, on 3 September 2013. The release had long been expected to be numbered 5.0 and called 'Key Lime Pie'. KitKat debuted on Google's Nexus 5, and has been optimised to run on a greater range of devices, having 512 MB of RAM as a recommended minimum.
Minimum hardware requirements have been upgraded in steps over time, with the new Android versions releases. Original minimums were 32 MB of RAM, 32 MB of Flash memory, and a 200 MHzARM architecture (ARMv5) processor.
As of November 2013 and version 4.4, Android requires at least 512 MB of RAM and an ARMv7 processor.MIPS and x86 architectures are also supported. OpenGL ES 2.0 hardware acceleration is still mandatory, while OpenGL ES 3.0 is supported.