Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia. Modern amphibians are all Lissamphibia, they inhabit a wide variety of habitats, with most species living within terrestrial, arboreal or freshwater aquatic ecosystems. Thus amphibians start out as larvae living in water, but some species have developed behavioural adaptations to bypass this; the young undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely on their skin, they are superficially similar to lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are ecological indicators; the earliest amphibians evolved in the Devonian period from sarcopterygian fish with lungs and bony-limbed fins, features that were helpful in adapting to dry land.
They diversified and became dominant during the Carboniferous and Permian periods, but were displaced by reptiles and other vertebrates. Over time, amphibians shrank in size and decreased in diversity, leaving only the modern subclass Lissamphibia; the three modern orders of amphibians are Anura and Apoda. The number of known amphibian species is 8,000, of which nearly 90% are frogs; the smallest amphibian in the world is a frog from New Guinea with a length of just 7.7 mm. The largest living amphibian is the 1.8 m Chinese giant salamander, but this is dwarfed by the extinct 9 m Prionosuchus from the middle Permian of Brazil. The study of amphibians is called batrachology, while the study of both reptiles and amphibians is called herpetology; the word "amphibian" is derived from the Ancient Greek term ἀμφίβιος, which means "both kinds of life", ἀμφί meaning "of both kinds" and βιος meaning "life". The term was used as a general adjective for animals that could live on land or in water, including seals and otters.
Traditionally, the class Amphibia includes all tetrapod vertebrates. Amphibia in its widest sense was divided into three subclasses, two of which are extinct: Subclass Lepospondyli† Subclass Temnospondyli† Subclass Lissamphibia Salientia: Jurassic to present—6,200 current species in 53 families Caudata: Jurassic to present—652 current species in 9 families Gymnophiona: Jurassic to present—192 current species in 10 families The actual number of species in each group depends on the taxonomic classification followed; the two most common systems are the classification adopted by the website AmphibiaWeb, University of California and the classification by herpetologist Darrel Frost and the American Museum of Natural History, available as the online reference database "Amphibian Species of the World". The numbers of species cited above follows Frost and the total number of known amphibian species as of March 31, 2019 is 8,000, of which nearly 90% are frogs. With the phylogenetic classification, the taxon Labyrinthodontia has been discarded as it is a polyparaphyletic group without unique defining features apart from shared primitive characteristics.
Classification varies according to the preferred phylogeny of the author and whether they use a stem-based or a node-based classification. Traditionally, amphibians as a class are defined as all tetrapods with a larval stage, while the group that includes the common ancestors of all living amphibians and all their descendants is called Lissamphibia; the phylogeny of Paleozoic amphibians is uncertain, Lissamphibia may fall within extinct groups, like the Temnospondyli or the Lepospondyli, in some analyses in the amniotes. This means that advocates of phylogenetic nomenclature have removed a large number of basal Devonian and Carboniferous amphibian-type tetrapod groups that were placed in Amphibia in Linnaean taxonomy, included them elsewhere under cladistic taxonomy. If the common ancestor of amphibians and amniotes is included in Amphibia, it becomes a paraphyletic group. All modern amphibians are included in the subclass Lissamphibia, considered a clade, a group of species that have evolved from a common ancestor.
The three modern orders are Anura and Gymnophiona. It has been suggested that salamanders arose separately from a Temnospondyl-like ancestor, that caecilians are the sister group of the advanced reptiliomorph amphibians, thus of amniotes. Although the fossils of several older proto-frogs with primitive characteristics are known, the oldest "true frog" is Prosalirus bitis, from the Early Jurassic Kayenta Formation of Arizona, it is anatomically similar to modern frogs. The oldest known caecilian is another Early Jurassic species, Eocaecilia micropodia from Arizona; the earliest salamander is Beiyanerpeton jianpingensis from the Late Jurassic of northeastern China. Authorities disagree as to whether Salientia is a superorder that includes the order Anura, or whether
GIMP is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, converting between different image formats, more specialized tasks. GIMP is released under GPLv3+ licenses and is available for Linux, macOS, Microsoft Windows. GIMP was released as the General Image Manipulation Program. In 1995 Spencer Kimball and Peter Mattis began developing GIMP as a semester-long project at the University of California, Berkeley for the eXperimental Computing Facility. In 1996 GIMP was released as the first publicly available release. In the following year Richard Stallman visited UC Berkeley where Spencer Kimball and Peter Mattis asked if they could change General to GNU. Richard Stallman approved and the definition of the acronym GIMP was changed to be the GNU Image Manipulation Program; this reflected its new existence as being developed as Free Software as a part of the GNU Project. The number of computer architectures and operating systems supported has expanded since its first release.
The first release supported UNIX systems, such as Linux, SGI IRIX and HP-UX. Since the initial release, GIMP has been ported to many operating systems, including Microsoft Windows and macOS. Following the first release, GIMP was adopted and a community of contributors formed; the community began developing tutorials and shared better work-flows and techniques. A GUI toolkit called GTK was developed to facilitate the development of GIMP. GTK was replaced by its successor GTK+ after being redesigned using object-oriented programming techniques; the development of GTK+ has been attributed to Peter Mattis becoming disenchanted with the Motif toolkit GIMP used. GIMP is developed by volunteers as a free software project associated with both the GNU and GNOME Projects. Development takes place in a public git source code repository, on public mailing lists and in public chat channels on the GIMPNET IRC network. New features are held in public separate source code branches and merged into the main branch when the GIMP team is sure they won't damage existing functions.
Sometimes this means that features that appear complete do not get merged or take months or years before they become available in GIMP. GIMP itself is released as source code. After a source code release installers and packages are made for different operating systems by parties who might not be in contact with the maintainers of GIMP; the version number used in GIMP is expressed in a major-minor-micro format, with each number carrying a specific meaning: the first number is incremented only for major developments. The second number is incremented with each release of new features, with odd numbers reserved for in-progress development versions and numbers assigned to stable releases; each year GIMP applies for several positions in the Google Summer of Code. From 2006 to 2009 there have been nine GSoC projects that have been listed as successful, although not all successful projects have been merged into GIMP immediately; the healing brush and perspective clone tools and Ruby bindings were created as part of the 2006 GSoC and can be used in version 2.8.0 of GIMP, although there were three other projects that were completed and are available in a stable version of GIMP.
Several of the GSoC projects were completed in 2008, but have been merged into a stable GIMP release in 2009 to 2014 for Version 2.8.xx and 2.9.x. Some of them needed some more code work for the master tree. Second public Development 2.9-Version was 2.9.4 with many deep improvements after initial Public Version 2.9.2 Third Public 2.9-Development version is Version 2.9.6. One of the new features is removing the 4GB size limit of XCF file. Increase of possible threads to 64 is an important point for modern parallel execution in actual AMD Ryzen and Intel Xeon processors. Version 2.9.8 included many bug improvements in gradients and clips. Improvements in performance and optimization beyond bug hunting were the development targets for 2.10.0. MacOS Beta is available with Version 2.10.4 The next stable version in the roadmap is 3.0 with a GTK3 port. The user interface of GIMP is designed by a dedicated usability team; this team was formed. A user interface brainstorming group has since been created for GIMP, where users of GIMP can send in their suggestions as to how they think the GIMP user interface could be improved.
GIMP is presented in two forms and multiple window mode. In multiple-window mode a set of windows contains all GIMP's functionality. By default and tool settings are on the left and other dialogues are on the right. A layers tab is to the right of the tools tab, allows a user to work individually on separate image layers. Layers can be edited by right-clicking on a particular layer to bring up edit options for that layer; the tools tab and layers tab are the most common dockable tabs. The Libre Graphics Meeting (L
Wacom Co. Ltd. is a Japanese company headquartered in Kazo, Japan, that specializes in graphics tablets and related products. The American headquarters are located in the Pearl District of Portland and those for Europe, Middle East, Africa in Duesseldorf, Germany. Wacom is a Japanese portmanteau: Wa for "harmony", "circle" or "Japan" and Com shortened for "computer". Wacom tablets are notable for their use of a patented cordless, battery-free, pressure-sensitive stylus or digital pen. In addition to manufacturing and selling tablets, Wacom provides graphical input technology for some tablet computers, which it calls "Penabled Technology". Wacom tablet functionality was used in the screen of the Compaq Concerto computer in 1992, making it an early tablet computer. In 1991, Wacom chips were used in the Samsung Penmaster tablet computer, sold as the GridPad SL by Grid Systems; the Penmaster had an early precursor to Samsung's S Pen, known today for its inclusion in the Galaxy Note line of phones.
Wacom produces several tablet lines, three of which are marketed worldwide. Most are sold with a software bundle, such as ArtRage Lite, Corel Painter Essentials and Photoshop Elements, which take advantage of the tablet features; each is sold with a compatible digital pen. Some pens feature buttons on an "eraser" at the other end; some models include a puck based on the same technology. Software drivers for recent versions of Mac OS X and Microsoft Windows are included with most models. All current models of external tablets connect to computers via Bluetooth. 2015 models † feature a resolution of 2540 lines per inch. Each of the models have a 5.8 × 3.6 in active surface area, a weight of 290 ±50g, 4 control buttons. Intuos tablets feature a battery-free pen, which can be used alongside finger swipes, with ± 0.02 in accuracy. Each tablet includes an option to switch orientation for left- or right-handed users. In the Americas and Europe, four models are† available in 2015: Intuos Draw, Intuos Art, Intuos Photo, Intuos Comic.
In addition to stylus-based input, each model features multi-touch functionality, with support for one- and two-finger gestures for such operations as scrolling and zooming. Wacom's Wireless Accessory Kit is a USB dongle and adapter which allows all Intuos tablet Models connect to a computer wirelessly; this kit is compatible with certain models. It did not work with the 2011 Bamboo Bamboo Connect or Bamboo Pen models; this kit was not compatible with older models, as the USB connection cable was hardwired to the tablet. The newer models feature a removable USB cable. ^† As of November 18, 2012 Intuos Pro is marketed to professional graphic artists and featured the highest specifications of any non-screen Wacom device. The Intuos Pro is available in multiple sizes and proportions and includes 60 degrees of tilt sensitivity and 2048 pressure levels, it has touch controls on the drawing surface, allowing the user to manipulate the canvas with multi-touch gestures. The Intuos line offered 2000 lines per cm resolution and came in multiple sizes: Small: 157.5 mm × 98.4 mm.
A larger version of the previous generation of Intuos, the Intuos4 Extra Large was still manufactured in 2011 and marketed to artists who needed a larger working area. The Intuos4 XL had a 462 mm × 304.8 mm. However, the Intuos4 lacked touch-based input, instead requiring a compatible mouse; the Cintiq is a tablet/screen hybrid, a graphics tablet that incorporates an LCD into the digitizing tablet itself, allowing the user to draw directly on the display surface. The tablets are available in several sizes. A 21-inch 1600×1200 resolution tablet, the 21UX, was available for several years at various price points; as of November 2007, both a 12-inch and a 20-inch widescreen model were released, the 12WX and the 20WSX, respectively. All three models use Intuos3 pens with 1024 pressure levels. In 2010, the 21UX saw a price drop, it offered a higher pen resolution and 2048 pressure levels due to Wacom's integration of Intuos4 technology. The 21UX's sensitivity was much greater than most tablet computers and portable computers offering similar functionality on built-in screens.
In addition, the 21UX included an integrated stand that allowed the user to tilt and rotate the unit. On September 13, 2011, Wacom announced the largest Cintiq at that time, it contained a 24-inch 1920×1200 resolution LCD with 92% coverage of the Adobe RGB color gamut. The pen technology, like the 21UX, was identical to the Intuos4 in resolution per inch and sensitivity; this model included an integrated adjustable-tilt stand that allowed it to hang off the edge of the table and closer to the user. Wacom debuted the Cintiq 27QHD at CES 2015; the Cintiq 27QHD, as per its name, sported a 27-inch Quad-HD resolution display. Included was an ExpressKey Remote, which replaced dedicated physical hotkeys on the sides of previous Cintiqs, could be used wirelessly and would adhere to the bezels of the 27QHD magnetically; the 27QHD had an advertised 97% of AdobeRGB coverage, 1.07 billion colors, REC 709 for
The Linux kernel is a free and open-source, Unix-like operating system kernel. The Linux family of operating systems is based on this kernel and deployed on both traditional computer systems such as personal computers and servers in the form of Linux distributions, on various embedded devices such as routers, wireless access points, PBXes, set-top boxes, FTA receivers, smart TVs, PVRs, NAS appliances. While the adoption of the Linux kernel in desktop computer operating system is low, Linux-based operating systems dominate nearly every other segment of computing, from mobile devices to mainframes; as of November 2017, all of the world's 500 most powerful supercomputers run Linux. The Android operating system for tablet computers and smartwatches uses the Linux kernel; the Linux kernel was conceived and created in 1991 by Linus Torvalds for his personal computer and with no cross-platform intentions, but has since expanded to support a huge array of computer architectures, many more than other operating systems or kernels.
Linux attracted developers and users who adopted it as the kernel for other free software projects, notably the GNU Operating System, created as a free, non-proprietary operating system, based on UNIX as a by-product of the fallout of the Unix wars. The Linux kernel API, the application programming interface through which user programs interact with the kernel, is meant to be stable and to not break userspace programs; as part of the kernel's functionality, device drivers control the hardware. However, the interface between the kernel and loadable kernel modules, unlike in many other kernels and operating systems, is not meant to be stable by design; the Linux kernel, developed by contributors worldwide, is a prominent example of free and open source software. Day-to-day development discussions take place on the Linux kernel mailing list; the Linux kernel is released under the GNU General Public License version 2, with some firmware images released under various non-free licenses. In April 1991, Linus Torvalds, at the time a 21-year-old computer science student at the University of Helsinki, started working on some simple ideas for an operating system.
He started with a task switcher in a terminal driver. On 25 August 1991, Torvalds posted the following to comp.os.minix, a newsgroup on Usenet: I'm doing a operating system for 386 AT clones. This has been brewing since April, is starting to get ready. I'd like any feedback on things people like/dislike in minix. I've ported bash and gcc, things seem to work; this implies that I'll get something practical within a few months Yes - it's free of any minix code, it has a multi-threaded fs. It is NOT portable, it never will support anything other than AT-harddisks, as that's all I have:-(. It's in C, but most people wouldn't call what I write C, it uses every conceivable feature of the 386 I could find, as it was a project to teach me about the 386. As mentioned, it uses a MMU, for both paging and segmentation. It's the segmentation; some of my "C"-files are as much assembler as C. Unlike minix, I happen to LIKE interrupts, so interrupts are handled without trying to hide the reason behind them. After that, many people contributed code to the project.
Early on, the MINIX community contributed code and ideas to the Linux kernel. At the time, the GNU Project had created many of the components required for a free operating system, but its own kernel, GNU Hurd, was incomplete and unavailable; the Berkeley Software Distribution had not yet freed itself from legal encumbrances. Despite the limited functionality of the early versions, Linux gained developers and users. In September 1991, Torvalds released version 0.01 of the Linux kernel on the FTP server of the Finnish University and Research Network. It had 10,239 lines of code. On 5 October 1991, version 0.02 of the Linux kernel was released. Torvalds assigned version 0 to the kernel to indicate that it was for testing and not intended for productive use. In December 1991, Linux kernel 0.11 was released. This version was the first to be self-hosted as Linux kernel 0.11 could be compiled by a computer running the same kernel version. When Torvalds released version 0.12 in February 1992, he adopted the GNU General Public License version 2 over his previous self-drafted license, which had not permitted commercial redistribution.
On 19 January 1992, the first post to the new newsgroup alt.os.linux was submitted. On 31 March 1992, the newsgroup was renamed comp.os.linux. The fact that Linux is a monolithic kernel rather than a microkernel was the topic of a debate between Andrew S. Tanenbaum, the creator of MINIX, Torvalds; this discussion is known as the Tanenbaum–Torvalds debate and started in 1992 on the Usenet discussion group comp.os.minix as a general debate about Linux and kernel architecture. Tanenbaum argued that microkernels were superior to monolithic kernels and that therefore Linux was obsolete. Unlike traditional monolithic kernels, device drivers in Linux are configured as loadable kernel modules and are loaded or unloaded while
X86 is a family of instruction set architectures based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a 16-bit extension of Intel's 8-bit 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address; the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors. Many additions and extensions have been added to the x86 instruction set over the years consistently with full backward compatibility; the architecture has been implemented in processors from Intel, Cyrix, AMD, VIA and many other companies. Of those, only Intel, AMD, VIA hold x86 architectural licenses, are producing modern 64-bit designs; the term is not synonymous with IBM PC compatibility, as this implies a multitude of other computer hardware. As of 2018, the majority of personal computers and laptops sold are based on the x86 architecture, while other categories—especially high-volume mobile categories such as smartphones or tablets—are dominated by ARM.
In the 1980s and early 1990s, when the 8088 and 80286 were still in common use, the term x86 represented any 8086 compatible CPU. Today, however, x86 implies a binary compatibility with the 32-bit instruction set of the 80386; this is due to the fact that this instruction set has become something of a lowest common denominator for many modern operating systems and also because the term became common after the introduction of the 80386 in 1985. A few years after the introduction of the 8086 and 8088, Intel added some complexity to its naming scheme and terminology as the "iAPX" of the ambitious but ill-fated Intel iAPX 432 processor was tried on the more successful 8086 family of chips, applied as a kind of system-level prefix. An 8086 system, including coprocessors such as 8087 and 8089, as well as simpler Intel-specific system chips, was thereby described as an iAPX 86 system. There were terms iRMX, iSBC, iSBX – all together under the heading Microsystem 80. However, this naming scheme was quite temporary.
Although the 8086 was developed for embedded systems and small multi-user or single-user computers as a response to the successful 8080-compatible Zilog Z80, the x86 line soon grew in features and processing power. Today, x86 is ubiquitous in both stationary and portable personal computers, is used in midrange computers, workstations and most new supercomputer clusters of the TOP500 list. A large amount of software, including a large list of x86 operating systems are using x86-based hardware. Modern x86 is uncommon in embedded systems and small low power applications as well as low-cost microprocessor markets, such as home appliances and toys, lack any significant x86 presence. Simple 8-bit and 16-bit based architectures are common here, although the x86-compatible VIA C7, VIA Nano, AMD's Geode, Athlon Neo and Intel Atom are examples of 32- and 64-bit designs used in some low power and low cost segments. There have been several attempts, including by Intel itself, to end the market dominance of the "inelegant" x86 architecture designed directly from the first simple 8-bit microprocessors.
Examples of this are the iAPX 432, the Intel 960, Intel 860 and the Intel/Hewlett-Packard Itanium architecture. However, the continuous refinement of x86 microarchitectures and semiconductor manufacturing would make it hard to replace x86 in many segments. AMD's 64-bit extension of x86 and the scalability of x86 chips such as the eight-core Intel Xeon and 12-core AMD Opteron is underlining x86 as an example of how continuous refinement of established industry standards can resist the competition from new architectures; the table below lists processor models and model series implementing variations of the x86 instruction set, in chronological order. Each line item is characterized by improved or commercially successful processor microarchitecture designs. At various times, companies such as IBM, NEC, AMD, TI, STM, Fujitsu, OKI, Cyrix, Intersil, C&T, NexGen, UMC, DM&P started to design or manufacture x86 processors intended for personal computers as well as embedded systems; such x86 implementations are simple copies but employ different internal microarchitectures as well as different solutions at the electronic and physical levels.
Quite early compatible microprocessors were 16-bit, while 32-bit designs were developed much later. For the personal computer market, real quantities started to appear around 1990 with i386 and i486 compatible processors named to Intel's original chips. Other companies, which designed or manufactured x86 or x87 processors, include ITT Corporation, National Semiconductor, ULSI System Technology, Weitek. Following the pipelined i486, Intel introduced the Pentium brand name for their new set of superscalar x86 designs.
The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, whilst the machine feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls, process controls; the design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. The goal of user interface design is to produce a user interface which makes it easy and enjoyable to operate a machine in the way which produces the desired result; this means that the operator needs to provide minimal input to achieve the desired output, that the machine minimizes undesired outputs to the human. User interfaces are composed of one or more layers including a human-machine interface interfaces machines with physical input hardware such a keyboards, game pads and output hardware such as computer monitors and printers.
A device that implements a HMI is called a human interface device. Other terms for human-machine interfaces are man–machine interface and when the machine in question is a computer human–computer interface. Additional UI layers may interact with one or more human sense, including: tactile UI, visual UI, auditory UI, olfactory UI, equilibrial UI, gustatory UI. Composite user interfaces are UIs that interact with two or more senses; the most common CUI is a graphical user interface, composed of a tactile UI and a visual UI capable of displaying graphics. When sound is added to a GUI it becomes a multimedia user interface. There are three broad categories of CUI: standard and augmented. Standard composite user interfaces use standard human interface devices like keyboards and computer monitors; when the CUI blocks out the real world to create a virtual reality, the CUI is virtual and uses a virtual reality interface. When the CUI does not block out the real world and creates augmented reality, the CUI is augmented and uses an augmented reality interface.
When a UI interacts with all human senses, it is called a qualia interface, named after the theory of qualia. CUI may be classified by how many senses they interact with as either an X-sense virtual reality interface or X-sense augmented reality interface, where X is the number of senses interfaced with. For example, a Smell-O-Vision is a 3-sense Standard CUI with visual display and smells; the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the physical part of the Human Machine Interface which we can see and touch. In complex systems, the human–machine interface is computerized; the term human–computer interface refers to this kind of system. In the context of computing, the term extends as well to the software dedicated to control the physical elements used for human-computer interaction; the engineering of the human–machine interfaces is enhanced by considering ergonomics.
The corresponding disciplines are human factors engineering and usability engineering, part of systems engineering. Tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the expression graphical user interface for human–machine interface on computers, as nearly all of them are now using graphics. There is a difference between a user interface and an operator interface or a human–machine interface; the term "user interface" is used in the context of computer systems and electronic devices Where a network of equipment or computers are interlinked through an MES -or Host to display information. A human-machine interface is local to one machine or piece of equipment, is the interface method between the human and the equipment/machine. An operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled.
The system may expose several user interfaces to serve different kinds of users. For example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel; the user interface of a mechanical system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI. In practice, the abbreviation MMI is still used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is more used for human–computer interaction. Other terms used are operator interface terminal; however it is abbreviated, the terms refer to the'layer' that separates a human, operating a machine from the machine itself. Without a clean and usable interface, humans would not be able to
Android (operating system)
Android is a mobile operating system developed by Google. It is based on a modified version of the Linux kernel and other open source software, is designed for touchscreen mobile devices such as smartphones and tablets. In addition, Google has further developed Android TV for televisions, Android Auto for cars, Wear OS for wrist watches, each with a specialized user interface. Variants of Android are used on game consoles, digital cameras, PCs and other electronics. Developed by Android Inc. which Google bought in 2005, Android was unveiled in 2007, with the first commercial Android device launched in September 2008. The operating system has since gone through multiple major releases, with the current version being 9 "Pie", released in August 2018. Google released the first Android Q beta on all Pixel phones on March 13, 2019; the core Android source code is known as Android Open Source Project, is licensed under the Apache License. Android is associated with a suite of proprietary software developed by Google, called Google Mobile Services that frequently comes pre-installed in devices, which includes the Google Chrome web browser and Google Search and always includes core apps for services such as Gmail, as well as the application store and digital distribution platform Google Play, associated development platform.
These apps are licensed by manufacturers of Android devices certified under standards imposed by Google, but AOSP has been used as the basis of competing Android ecosystems, such as Amazon.com's Fire OS, which use their own equivalents to GMS. Android has been the best-selling OS worldwide on smartphones since 2011 and on tablets since 2013; as of May 2017, it has over two billion monthly active users, the largest installed base of any operating system, as of December 2018, the Google Play store features over 2.6 million apps. The name Andrew and the noun Android share the Greek root andros. Andy Rubin picked android.com as his personal website, his colleagues used Android as his nickname at work. That became the name of the company he founded, the name of the operating system they developed. Android Inc. was founded in Palo Alto, California, in October 2003 by Andy Rubin, Rich Miner, Nick Sears, Chris White. Rubin described the Android project as "tremendous potential in developing smarter mobile devices that are more aware of its owner's location and preferences".
The early intentions of the company were to develop an advanced operating system for digital cameras, this was the basis of its pitch to investors in April 2004. The company decided that the market for cameras was not large enough for its goals, by five months it had diverted its efforts and was pitching Android as a handset operating system that would rival Symbian and Microsoft Windows Mobile. Rubin had difficulty attracting investors early on, Android was facing eviction from its office space. Steve Perlman, a close friend of Rubin, brought him $10,000 in cash in an envelope, shortly thereafter wired an undisclosed amount as seed funding. Perlman refused a stake in the company, has stated "I did it because I believed in the thing, I wanted to help Andy."In July 2005, Google acquired Android Inc. for at least $50 million. Its key employees, including Rubin and White, joined Google as part of the acquisition. Not much was known about the secretive Android at the time, with the company having provided few details other than that it was making software for mobile phones.
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 promise of providing a flexible, upgradeable system. Google had "lined up a series of hardware components and software partners and signaled to carriers that it was open to various degrees of cooperation". Speculation about Google's intention to enter the mobile communications market continued to build through December 2006. An early prototype had a close resemblance to a BlackBerry phone, with no touchscreen and a physical QWERTY keyboard, but the arrival of 2007's Apple iPhone meant that Android "had to go back to the drawing board". Google changed its Android specification documents to state that "Touchscreens will be supported", although "the Product was designed with the presence of discrete physical buttons as an assumption, therefore a touchscreen cannot replace physical buttons". By 2008, both Nokia and BlackBerry announced touch-based smartphones to rival the iPhone 3G, Android's focus switched to just touchscreens.
The first commercially available smartphone running Android was the HTC Dream known as T-Mobile G1, announced on September 23, 2008. On November 5, 2007, the Open Handset Alliance, a consortium of technology companies including Google, device manufacturers such as HTC, Motorola and Samsung, wireless carriers such as Sprint and T-Mobile, chipset makers such as Qualcomm and Texas Instruments, unveiled itself, with a goal to develop "the first open and comprehensive platform for mobile devices". Within a year, the Open Handset Alliance faced two other open source competitors, the Symbian Foundation and the LiMo Foundation, the latter developing a Linux-based mobile operating system like Google. In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony. Since 2008, Android has seen numerous updates which have incrementally improved the operating system, adding new features and fixing bugs in previous releases.
Each major release is named in alphabetical order after a dessert or sugary treat, with the first few Android versions being called "Cupcake", "Donut"