Android is a mobile operating system initially developed by Android Inc., a firm purchased by Google in 2005. Android is based upon a modified version of the Linux kernel. Google and other members of the Open Handset Alliance collaborated to develop and release Android to the world. The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android. Unit sales for Android OS smartphones ranked first among all smartphone OS handsets sold in the U.S. in the second and third quarters of 2010, with a third quarter market share of 43.6%.
Android has a large community of developers writing application programs (“apps”) that extend the functionality of the devices. There are currently over 100,000 apps available for Android. Android Market is the online app store run by Google, though apps can be downloaded from third party sites (except on AT&T, which disallows this). Developers write 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 78 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 operating system 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. The Android operating system consists of 12 million lines of code including 3 million lines of XML, 2.8 million lines of C, 2.1 million lines of Java, and 1.75 million lines of C++.
Acquisition by Google
In July 2005, Google acquired Android Inc., a small startup company based in Palo Alto, California, USA. Android’s co-founders who went to work at Google included Andy Rubin(co-founder of Danger), Rich Miner (co-founder of Wildfire Communications, Inc.), Nick Sears (once VP at T-Mobile), and Chris White (headed design and interface development at WebTV). At the time, little was known about the functions of Android, Inc. other than that they made software for mobile phones. This began rumors that Google was planning to enter the mobile phone market.
At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel which they marketed to handset makers and carriers on the premise of providing a flexible, upgradable system. It was reported that Google had already lined up a series of hardware component and software partners and signaled to carriers that it was open to various degrees of cooperation on their part. More speculation that Google would be entering the mobile-phone market came in December 2006. Reports from the BBCand The Wall Street Journal noted that Google wanted its search and applications on mobile phones and it was working hard to deliver that. Print and online media outlets soon reported rumors that Google was developing a Google-branded handset. More speculation followed reporting that as Google was defining technical specifications, it was showing prototypes to cell phone manufacturers and network operators.
In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.
Open Handset Alliance
On the 5th of November 2007. the Open Handset Alliance, a consortium of several companies which include Texas Instruments,Broadcom Corporation, Google, HTC, Intel, LG, Marvell Technology Group, Motorola, Nvidia, Qualcomm, Samsung Electronics,Sprint Nextel and T-Mobile was unveiled with the goal to develop open standards for mobile devices. Along with the formation of the Open Handset Alliance, the OHA also unveiled their first product, Android, a mobile device platform built on the Linux kernelversion 2.6.
On 9 December 2008, it was announced that 14 new members would be joining the Android Project, including PacketVideo, ARM Holdings, Atheros Communications, Asustek Computer Inc, Garmin Ltd, Softbank, Sony Ericsson, Toshiba Corp, and Vodafone Group Plc.
With the exception of brief update periods, Android has been available under a free software / open source license since 21 October 2008. Google published the entire source code (including network and telephony stacks) under an Apache License.
The Apache License allows vendors to add proprietary extensions without submitting them back to the open source community.
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 update to the Android operating system is developed under a code name based on a dessert item.
Released 9 February 2009
Based on Linux Kernel 2.6.27
On 30 April 2009, the official 1.5 (Cupcake) update for Android was released. There were several new features and UI updates included in the 1.5 update:
- Ability to record and watch videos through camcorder mode
- Uploading videos to YouTube and pictures to Picasa directly from the phone
- A new soft-keyboard with text-prediction
- Bluetooth A2DP and AVRCP support
- Ability to automatically connect to a Bluetooth headset within a certain distance
- New widgets and folders that can populate the Home screens
- Animated screen transitions
Based on Linux Kernel 2.6.29
On 15 September 2009, the 1.6 (Donut) SDK was released. Included in the update were:
- An improved Android Market experience
- An integrated camera, camcorder, and gallery interface
- Gallery now enables users to select multiple photos for deletion
- Updated Voice Search, with faster response and deeper integration with native applications, including the ability to dial contacts
- Updated search experience to allow searching bookmarks, history, contacts, and the web from the home screen
- Updated technology support for CDMA/EVDO, 802.1x, VPNs, and a text-to-speech engine
- Support for WVGA screen resolutions
- Speed improvements in searching and camera applications
- Gesture framework and GestureBuilder development tool
- Google free turn-by-turn navigation
2.0 / 2.1 (Eclair)
Based on Linux Kernel 2.6.29
On 26 October 2009, the 2.0 (Eclair) SDK was released. Among the changes were:
- Optimized hardware speed
- Support for more screen sizes and resolutions
- Revamped UI
- New Browser UI and HTML5 support
- New contact lists
- Better contrast ratio for backgrounds
- Improved Google Maps 3.1.2
- Microsoft Exchange support
- Built in flash support for Camera
- Digital Zoom
- MotionEvent class enhanced to track multi-touch events
- Improved virtual keyboard
- Bluetooth 2.1
- Live Wallpapers
The 2.0.1 SDK was released on 3 December 2009.
The 2.1 SDK was released on 12 January 2010.
Based on Linux Kernel 2.6.32
On 20 May 2010, the 2.2 (Froyo – Frozen Yogurt) SDK was released. Changes included:
- General Android OS speed, memory, and performance optimizations
- Additional application speed improvements courtesy of JIT implementation
- Increased Microsoft Exchange support (security policies, auto-discovery, GAL look-up, calendar synchronization, remote wipe)
- Improved application launcher with shortcuts to Phone and Browser applications
- USB tethering and Wi-Fi hotspot functionality
- Added an option to disable data access over mobile network
- Updated Market application with batch and automatic update features
- Quick switching between multiple keyboard languages and their dictionaries
- Voice dialing and contact sharing over Bluetooth
- Support for numeric and alphanumeric passwords
- Support for file upload fields in the Browser application
- Browser can now display animated GIFs (instead of just the first frame)
- Support for installing applications to the expandable memory
- Adobe Flash 10.1 support
Based on Linux Kernel 220.127.116.11
Confirmed new features of 2.3 (Gingerbread):
- Support for WebM video playback
- Support for Near Field Communication
Unconfirmed new features:
- Improved copy–paste functionalities
- Improved social networking features
- Android Market music store
- Media streaming from PC library
- Revamped UI
- Support for bigger screens with up to Wide XGA (1366×768) resolution
- New 3D Games support including new Marketplace area for gaming
- Use of mksh for /system/bin/sh
- Support for video calls
- Support for WebP image files
- Support for Google TV
Scheduled for early 2011 launch. Feature list started with features that won’t make the cut-off for Gingerbread
? (Ice Cream)
Supposed mid 2011 launch.
Source : wikipedia