ANDROID (operating system)

Android (operating system) Android Home screen displayed by Samsung Nexus S with Google, running Android 2.3 "Gingerbread" Company / developer Google Inc, Open Handset Alliance Programmed in XML, C (core),[1] Java (UI), C++ Working state Current Source model Mixed (free and open source software and proprietary software)[2][3] Initial release 21 October 2008 Latest stable release Tablets: 3.2 (Honeycomb)[4] Phones: 2.3.5 (Gingerbread) / 25 July 2011; 31 days ago[4] Package manager APK Supported platforms ARM, MIPS,[5] x86[6][citation needed] Kernel type Linux kernel (monolithic) Default user interface Graphical License Apache License 2.0 before 3.0, closed source for 3.0, 3.1 and 3.2: Linux kernel patches under GNU GPL v2[7] Official website http://www.android.com/ History Foundation Android, Inc. was founded in Palo Alto, California, United States in October, 2003 by 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)to develop, in Rubin's words "...smarter mobile devices that are more aware of its owner's location and preferences".[27] Despite the obvious past accomplishments of the founders and early employees, Android Inc. operated secretively, revealing only that it was working on software for mobile phones.[27] That same year, Rubin ran out of cash. Steve Perlman brought him $10,000 in cash in an envelope and refused a stake in the company.[28] Acquisition by Google Google acquired Android Inc. in August 2005, making Android Inc. a wholly owned subsidiary of Google Inc. Key employees of Android Inc., including Andy Rubin, Rich Miner and Chris White, stayed at the company after the acquisition.[24] Not much was known about Android Inc. at the time of the acquisition, but many assumed that Google was planning to enter the mobile phone market with this move.[citation needed] Post-acquisition development At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the premise of providing a flexible, upgradable system. Google had 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.[29][30][31] Speculation about Google's intention to enter the mobile communications market continued to build through December 2006.[32] Reports from the BBC and 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.[33] Some speculated 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.[34][35] [edit] Open Handset Alliance Main article: Open Handset Alliance Today's announcement is more ambitious than any single 'Google Phone' that the press has been speculating about over the past few weeks. Our vision is that the powerful platform we're unveiling will power thousands of different phone models. Eric Schmidt, former Google Chairman/CEO[13] On November 5, 2007, the Open Handset Alliance, a consortium of several companies which include Broadcom Corporation, Google, HTC, Intel, LG, Marvell Technology Group, Motorola, Nvidia, Qualcomm, Samsung Electronics, Sprint Nextel, T-Mobile and Texas Instruments unveiled itself. The goal of the Open Handset Alliance is to develop open standards for mobile devices.[13] On the same day, the Open Handset Alliance also unveiled their first product, Android, a mobile device platform built on the Linux kernel version 2.6.[13] On December 9, 2008, 14 new members joined, including ARM Holdings, Atheros Communications, Asustek Computer Inc, Garmin Ltd, Huawei Technologies, PacketVideo, Softbank, Sony Ericsson, Toshiba Corp, and Vodafone Group Plc.[36][37] [edit] Licensing With the exception of brief update periods, Android has been available under a free and open source software license since October 21, 2008. Google published the entire source code (including network and telephony stacks)[38] under an Apache License.[39] Google also keeps the reviewed issues list publicly open for anyone to see and comment.[40] Even though the software is open-source, device manufacturers cannot use Google's Android trademark unless Google certifies that the device complies with their Compatibility Definition Document (CDD). Devices must also meet this definition to be eligible to license Google's closed-source applications, including the Android Market.[41] In September 2010, Skyhook Wireless filed a lawsuit against Google in which they alleged that Google had used the compatibility document to block Skyhook's mobile positioning service (XPS) from Motorola's Android mobile devices.[42] In December 2010 a judge denied Skyhook's motion for preliminary injunction, saying that Google had not closed off the possibility of accepting a revised version of Skyhook's XPS service, and that Motorola had terminated their contract with Skyhook because Skyhook wanted to disable Google's location data collection functions on Motorola's devices, which would have violated Motorola's obligations to Google and its carriers.[43] In early 2011, Google chose to temporarily withhold the source code to the tablet-only Honeycomb release, which called into question the "open-ness" of this Android release.[44] The reason, according to Andy Rubin in an official Android blog post, was because Honeycomb was rushed for production of the Motorola Xoom,[45] and they did not want third parties creating a "really bad user experience" by attempting to put onto smartphones a version of Android intended for tablets.[46] Google later confirmed that the Honeycomb source code would not be released until after it was merged with the Gingerbread release in Ice Cream Sandwich.[47] Version history Main article: Android version history 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.[48] • 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.[49] • 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[50] • 2.3 (Gingerbread) refined the user interface, improved the soft keyboard and copy/paste features, and added support for Near Field Communication[51] • 3.0 (Honeycomb) was a tablet-oriented[52][53][54] release which supports larger screen devices and introduces many new user interface features, and supports multicore processors and hardware acceleration for graphics.[55] The Honeycomb SDK has been released and the first device featuring this version, the Motorola Xoom tablet, went on sale in February 2011.[56] • 3.1 (Honeycomb) was announced at the 2011 Google I/O on 10 May 2011. - To allow honeycomb devices to directly transfer content from USB devices[57] • 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.[58] Future releases that have been announced include: • 4.0 (Ice Cream Sandwich)[59] is said to be a combination of Gingerbread and Honeycomb into a "cohesive whole".[60] It will be released in Q4 2011.[61] Design Android's kernel is derived from the Linux kernel. Google contributed code to the Linux kernel as part of their Android effort, but certain features, notably a power management feature called wakelocks, were rejected by mainline kernel developers, so the Android kernel is now a separate version or fork of the Linux kernel.[62][63][64] Google announced in April 2010 that they would hire two employees to work with the Linux kernel community.[65] Greg Kroah-Hartman, the current Linux kernel maintainer for the -stable branch, said in December 2010 that he was concerned that Google was no longer trying to get their code changes included in mainstream Linux.[63] Some Google Android developers hinted that "the Android team was getting fed up with the process", because they were a small team and had more urgent work to do on Android.[66] Android does not have a native X Window System nor does it support the full set of standard GNU libraries, and this makes it difficult to port existing GNU/Linux applications or libraries to Android.[67] However, support for the X Window System is possible.[68] Features The Android Emulator default home screen (v1.5) Architecture diagram Current features and specifications:[69][70][71] Handset layouts The platform is adaptable to larger, VGA, 2D graphics library, 3D graphics library based on OpenGL ES 2.0 specifications, and traditional smartphone layouts. Storage SQLite, a lightweight relational database, is used for data storage purposes. Connectivity Android supports connectivity technologies including GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX. Messaging SMS and MMS are available forms of messaging, including threaded text messaging and now Android Cloud To Device Messaging Framework(C2DM) is also a part of Android Push Messaging service. Multiple language support Android supports multiple human languages. The number of languages more than doubled for the platform 2.3 Gingerbread. Android lacks font rendering of several languages even after official announcements[citation needed] of added support (e.g. Hindi). Web browser The web browser available in Android is based on the open-source WebKit layout engine, coupled with Chrome's V8 JavaScript engine. The browser scores a 93/100 on the Acid3 Test. Java support While most Android applications are written in Java, there is no Java Virtual Machine in the platform and Java byte code is not executed. Java classes are compiled into Dalvik executables and run on Dalvik, a specialized virtual machine designed specifically for Android and optimized for battery-powered mobile devices with limited memory and CPU. J2ME support can be provided via third-party applications. Media support Android supports the following audio/video/still media formats: WebM, H.263, H.264 (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB (in 3GP container), AAC, HE-AAC (in MP4 or 3GP container), MP3, MIDI, Ogg Vorbis, FLAC, WAV, JPEG, PNG, GIF, BMP.[71] Streaming media support RTP/RTSP streaming (3GPP PSS, ISMA), HTML progressive download (HTML5