An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
Solaris (operating system)
Solaris is a Unix operating system developed by Sun Microsystems. It superseded their earlier SunOS in 1993. In 2010, after the Sun acquisition by Oracle, it was renamed Oracle Solaris. Solaris is known for its scalability on SPARC systems, for originating many innovative features such as DTrace, ZFS and Time Slider. Solaris supports SPARC and x86-64 servers from Oracle and other vendors. Solaris is registered as compliant with the Single UNIX Specification. Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, founded the OpenSolaris open-source project. With OpenSolaris, Sun wanted to build a user community around the software. After the acquisition of Sun Microsystems in January 2010, Oracle decided to discontinue the OpenSolaris distribution and the development model. In August 2010, Oracle discontinued providing public updates to the source code of the Solaris kernel turning Solaris 11 back into a closed source proprietary operating system.
Following that, in 2011 the Solaris 11 kernel source code leaked to BitTorrent. However, through the Oracle Technology Network, industry partners can still gain access to the in-development Solaris source code. Source code for the open source components of Solaris 11 is available for download from Oracle. In 1987, AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix variants on the market at that time: Berkeley Software Distribution, UNIX System V, Xenix; this became Unix System V Release 4. On September 4, 1991, Sun announced that it would replace its existing BSD-derived Unix, SunOS 4, with one based on SVR4; this was identified internally as SunOS 5, but a new marketing name was introduced at the same time: Solaris 2. The justification for this new overbrand was that it encompassed not only SunOS, but the OpenWindows graphical user interface and Open Network Computing functionality. Although SunOS 4.1.x micro releases were retroactively named Solaris 1 by Sun, the Solaris name is used exclusively to refer only to the releases based on SVR4-derived SunOS 5.0 and later.
For releases based on SunOS 5, the SunOS minor version is included in the Solaris release number. For example, Solaris 2.4 incorporates SunOS 5.4. After Solaris 2.6, the 2. was dropped from the release name, so Solaris 7 incorporates SunOS 5.7, the latest release SunOS 5.11 forms the core of Solaris 11.4. Although SunSoft stated in its initial Solaris 2 press release their intent to support both SPARC and x86 systems, the first two Solaris 2 releases, 2.0 and 2.1, were SPARC-only. An x86 version of Solaris 2.1 was released in June 1993, about 6 months after the SPARC version, as a desktop and uniprocessor workgroup server operating system. It included the Wabi emulator to support Windows applications. At the time, Sun offered the Interactive Unix system that it had acquired from Interactive Systems Corporation. In 1994, Sun released Solaris 2.4, supporting both SPARC and x86 systems from a unified source code base. On September 2, 2017, Simon Phipps, a former Sun Microsystems employee not hired by Oracle in the acquisition, reported on Twitter that Oracle had laid off the Solaris core development staff, which many interpreted as sign that Oracle no longer intended to support future development of the platform.
While Oracle did have a large layoff of Solaris development engineering staff, development continues today of which Solaris 11.4 was released in 2018. Solaris uses a common code base for the platforms it supports: i86pc. Solaris has a reputation for being well-suited to symmetric multiprocessing, supporting a large number of CPUs, it has been integrated with Sun's SPARC hardware, with which it is marketed as a combined package. This has led to more reliable systems, but at a cost premium compared to commodity PC hardware. However, it has supported x86 systems since Solaris 2.1 and 64-bit x86 applications since Solaris 10, allowing Sun to capitalize on the availability of commodity 64-bit CPUs based on the x86-64 architecture. Sun has marketed Solaris for use with both its own "x64" workstations and servers based on AMD Opteron and Intel Xeon processors, as well as x86 systems manufactured by companies such as Dell, Hewlett-Packard, IBM; as of 2009, the following vendors support Solaris for their x86 server systems: Dell – will "test and optimize Solaris and OpenSolaris on its rack and blade servers and offer them as one of several choices in the overall Dell software menu" Intel Hewlett Packard Enterprise – distributes and provides software technical support for Solaris on BL, DL, SL platforms Fujitsu SiemensAs of July 2010, Dell and HP certify and resell Oracle Solaris, Oracle Enterprise Linux and Oracle VM on their respective x86 platforms, IBM stopped direct support for Solaris on x64 kit.
Solaris 2.5.1 included support for the PowerPC platform, but the port was canceled before the Solaris 2.6 release. In January 2006, a community of developers at Blastwave began work on a PowerPC port which they named Polaris. In October 2006, an OpenSolaris community project based on the Blastwave efforts and Sun Labs' Project Pulsar, which re-integrated the relevant parts from Solaris 2.5.1 into OpenSolaris, announced its first official source code release. A port of Solaris to the Intel Itanium architecture was announced in 1997 but never brought to market. On November 28, 2007, IBM, Sine Nomine Associates demonstrated a preview of OpenSolaris for System z running on an IBM System z mainframe under z/VM, called Sirius
GNOME is a free and open-source desktop environment for Unix-like operating systems. GNOME was an acronym for GNU Network Object Model Environment, but the acronym was dropped because it no longer reflected the vision of the GNOME project. GNOME is part of the GNU Project and developed by The GNOME Project, composed of both volunteers and paid contributors, the largest corporate contributor being Red Hat, it is an international project that aims to develop software frameworks for the development of software, to program end-user applications based on these frameworks, to coordinate efforts for internationalization and localization and accessibility of that software. GNOME 3 is the default desktop environment on many major Linux distributions including Fedora, Ubuntu, SUSE Linux Enterprise, Red Hat Enterprise Linux, CentOS, Oracle Linux, Scientific Linux, SteamOS, Kali Linux and Endless OS; the continued fork of the last GNOME 2 release that goes under the name MATE is default on many distributions that targets low usage of system resources.
GNOME was started on August 15 1997 by Miguel de Icaza and Federico Mena as a free software project to develop a desktop environment and applications for it. It was founded in part because K Desktop Environment, growing in popularity, relied on the Qt widget toolkit which used a proprietary software license until version 2.0. In place of Qt, the GTK toolkit was chosen as the base of GNOME. GTK uses the GNU Lesser General Public License, a free software license that allows software linking to it to use a much wider set of licenses, including proprietary software licenses. GNOME itself is licensed under the LGPL for its libraries, the GNU General Public License for its applications; the name "GNOME" was an acronym of GNU Network Object Model Environment, referring to the original intention of creating a distributed object framework similar to Microsoft's OLE, but the acronym was dropped because it no longer reflected the vision of the GNOME project. The California startup Eazel developed the Nautilus file manager from 1999 to 2001.
De Icaza and Nat Friedman founded Helix Code in 1999 in Massachusetts. During the transition to GNOME 2 around the year 2001 and shortly thereafter there were brief talks about creating a GNOME Office suite. On September 15, 2003 GNOME-Office 1.0, consisting of AbiWord 2.0, GNOME-DB 1.0 and Gnumeric 1.2.0 was released. Although some release planning for GNOME Office 1.2 was happening on gnome-office mailing list, Gnumeric 1.4 was announced as a part of it, the 1.2 release of the suite itself never materialized. As of May 4, 2014 GNOME wiki only mentions "GNOME/Gtk applications that are useful in an office environment". GNOME 2 was similar to a conventional desktop interface, featuring a simple desktop in which users could interact with virtual objects, such as windows and files. GNOME 2 started out with Sawfish, but switched to Metacity as its default window manager; the handling of windows and files in GNOME 2 is similar to that of contemporary desktop operating systems. In the default configuration of GNOME 2, the desktop has a launcher menu for quick access to installed programs and file locations.
However, these features can be moved to any position or orientation the user desires, replaced with other functions or removed altogether. As of 2009, GNOME 2 was the default desktop for OpenSolaris. GNOME 1 and 2 followed the traditional desktop metaphor. GNOME 3, released in 2011, changed this with GNOME Shell, a more abstract metaphor where switching between different tasks and virtual desktops takes place in a separate area called "Overview". Since Mutter replaced Metacity as the default window manager, the minimize and maximize buttons no longer appear by default, the title bar, menu bar and tool bar combinated in one horizontal bar called "header bar" via Client-Side Decoration mechanism. Adwaita replaced Clearlooks as the default theme. Many GNOME Core Applications went through redesigns to provide a more consistent user experience; the release of GNOME 3, notable for its move away from the traditional menu bar and taskbar, has caused considerable controversy in the GNU and Linux community.
Many users and developers have expressed concerns about usability. A few projects have been initiated to continue development of GNOME 2.x or to modify GNOME 3.x to be more like the 2.x releases. GNOME 3 aims to provide a single interface for desktop computers and tablet computers; this means using only input techniques that work on all those devices, requiring abandonment of certain concepts to which desktop users were accustomed, such as right-clicking, or saving files on the desktop. These major changes evoked widespread criticism; the MATE desktop environment was forked from the GNOME 2 code-base with the intent of retaining the traditional GNOME 2 interface, whilst keeping compatibility with modern Linux technology, such as GTK 3. The Linux Mint team addressed the issue in another way by developing the "Mint GNOME Shell Extensions" that ran on top of GNOME Shell and allowed it to be used via the traditional desktop metaphor; this led to the creation of the Cinnamon user interface, forked from the GNOME 3 codebase.
Among those critical of the early releases of GNOME 3 is Linus Torvalds, the creator of the Linux kernel. Torvalds abandoned GNOME for a wh
In computing and telecommunications, a menu is a list of options or commands presented to the user of a computer or communications system. A menu may either be only part of a more complex one. A user chooses an option from a menu by using an input device; some input methods require linear navigation: the user must move a cursor or otherwise pass from one menu item to another until reaching the selection. On a computer terminal, a reverse video bar may serve as the cursor. Touch user interfaces and menus that accept codes to select menu options without navigation are two examples of non-linear interfaces; some of the input devices used in menu interfaces are touchscreens, mice, remote controls, microphones. In a voice-activated system, such as interactive voice response, a microphone sends a recording of the user's voice to a speech recognition system, which translates it to a command. A computer using a command line interface may present a list of relevant commands with assigned short-cuts on the screen.
Entering the appropriate short-cut selects a menu item. A more sophisticated solution offers navigation using the mouse; the current selection can be activated by pressing the enter key. A computer using a graphical user interface presents menus with a combination of text and symbols to represent choices. By clicking on one of the symbols or text, the operator is selecting the instruction that the symbol represents. A context menu is a menu in which the choices presented to the operator are automatically modified according to the current context in which the operator is working. A common use of menus is to provide convenient access to various operations such as saving or opening a file, quitting a program, or manipulating data. Most widget toolkits provide some form of pop-up menu. Pull-down menus are the type used in menu bars, which are most used for performing actions, whereas pop-up menus are more to be used for setting a value, might appear anywhere in a window. According to traditional human interface guidelines, menu names were always supposed to be verbs, such as "file", "edit" and so on.
This has been ignored in subsequent user interface developments. A single-word verb however is sometimes unclear, so as to allow for multiple word menu names, the idea of a vertical menu was invented, as seen in NeXTSTEP. Menus are now seen in consumer electronics, starting with TV sets and VCRs that gained on-screen displays in the early 1990s, extending into computer monitors and DVD players. Menus allow the control of settings like tint, contrast and treble, other functions such as channel memory and closed captioning. Other electronics with text-only displays can have menus, anything from business telephone systems with digital telephones, to weather radios that can be set to respond only to specific weather warnings in a specific area. Other more recent electronics in the 2000s have menus, such as digital media players. Menus are sometimes hierarchically organized, allowing navigation through different levels of the menu structure. Selecting a menu entry with an arrow will expand it, showing a second menu with options related to the selected entry.
Usability of submenus has been criticized as difficult, because of the narrow height that must be crossed by the pointer. The steering law predicts that this movement will be slow, any error in touching the boundaries of the parent menu entry will hide the submenu; some techniques proposed to alleviate these errors are keeping the submenu open while moving the pointer in diagonal, using mega menus designed to enhance scannability and categorization of its contents. In computer menu functions or buttons, an appended ellipsis means that upon selection, another dialog will follow, where the user can or must make a choice. If the ellipse is missing, the function will be executed upon selection. "Save": the file will be overwritten without further input. "Save as...": in the following dialog, the user can, for example, select another location or file name or other file format. Drop-down menu Federal Standard 1037C Hamburger button Pie menu Radio button WIMP MenUA: A Design Space of Menu Techniques—Site that discusses various menu design techniques
Linux is a family of free and open-source software operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is packaged in a Linux distribution. Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian and Ubuntu. Commercial distributions include SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, include a solution stack such as LAMP; because Linux is redistributable, anyone may create a distribution for any purpose. Linux was developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.
Linux is the leading operating system on servers and other big iron systems such as mainframe computers, the only OS used on TOP500 supercomputers. It is used by around 2.3 percent of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux runs on embedded systems, i.e. devices whose operating system is built into the firmware and is tailored to the system. This includes routers, automation controls, digital video recorders, video game consoles, smartwatches. Many smartphones and tablet computers run other Linux derivatives; because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux is one of the most prominent examples of open-source software collaboration; the source code may be used and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
The Unix operating system was conceived and implemented in 1969, at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna. First released in 1971, Unix was written in assembly language, as was common practice at the time. In a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie; the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, AT&T was required to license the operating system's source code to anyone who asked; as a result, Unix grew and became adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs; the GNU Project, started in 1983 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed of free software. Work began in 1984. In 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License in 1989.
By the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers and the kernel, called GNU/Hurd, were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, he would not have decided to write his own. Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has stated that if 386BSD had been available at the time, he would not have created Linux. MINIX was created by Andrew S. Tanenbaum, a computer science professor, released in 1987 as a minimal Unix-like operating system targeted at students and others who wanted to learn the operating system principles. Although the complete source code of MINIX was available, the licensing terms prevented it from being free software until the licensing changed in April 2000. In 1991, while attending the University of Helsinki, Torvalds became curious about operating systems.
Frustrated by the licensing of MINIX, which at the time limited it to educational use only, he began to work on his own operating system kernel, which became the Linux kernel. Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were used on Linux. Linux matured and further Linux kernel development took place on Linux systems. GNU applications replaced all MINIX components, because it was advantageous to use the available code from the GNU Project with the fledgling operating system. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmant
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
À la carte
In restaurants, à la carte is the practice of ordering individual dishes from a menu in a restaurant, as opposed to table d'hôte, where a set menu is offered. It is an early 19th century loan from French meaning "according to the menu"; the individual dishes to be ordered may include side dishes, or the side dishes may be offered separately, in which case, they are considered à la carte. The earliest examples of à la carte are from 1816 for the adjectival use and from 1821 for the adverbial use; these pre-date the use of the word menu. More broadly, the term is not exclusive to food. Today, it can be used in reference to things such as television. To watch television à la carte refers to paying for a provider where the viewer can choose from an option of programs to watch, instead of watching from set programs. Omakase Table d'hôte, the opposite of à la carte Buffet List of French words and phrases used by English speakers Pro rata, a method of billing or other calculation based on proportional usage Business and economics portal Food portal Baraban, R.
S.. F.. Successful Restaurant Design. John Wiley & Sons. Pp. 17–18. ISBN 978-0-470-25075-4. Committee on Nutrition Standards for Foods in Schools and Nutrition Board, Institute of Medicine. Nutrition Standards for Foods in Schools. National Academies Press. Page 83. Mosimann, Anton. Cuisine à la carte. Macmillan Publishers Limited. 304 pages. À la carte pricing strategy