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An XO-1 prototype
ManufacturerQuanta Computer
Media1 GB flash memory
Operating systemFedora-based (Linux) with Sugar GUI
CPUAMD Geode LX700@0.8 W + 5536
Memory256 MB DRAM
Displaydual-mode (backlit color, direct-sunlight grayscale) 19.1 cm (7.5 in) diagonal TFT LCD 1200×900
InputKeyboard, touchpad, microphone, camera
Camerabuilt-in video camera (640×480; 30 FPS)
Connectivity802.11b/g /s wireless LAN, 3 USB 2.0 ports, MMCSD card slot
PowerNiMH or LiFePO4 removable battery pack
Dimensions242 mm × 228 mm × 32 mm (9.5 in × 9.0 in × 1.3 in)
MassLiFePO4 battery: 1.45 kg (3.2 lb); NiMH battery: 1.58 kg (3.5 lb)

The OLPC XO (formerly known as $100 Laptop,[2] Children's Machine,[3] 2B1[4]) is a low cost laptop computer intended to be distributed to children in developing countries around the world,[5] to provide them with access to knowledge, and opportunities to "explore, experiment and express themselves" (constructionist learning).[6] The XO was developed by Nicholas Negroponte, a co-founder of MIT's Media Lab, and designed by Yves Behar's Fuseproject company.[7] The laptop is manufactured by Quanta Computer and developed by One Laptop per Child (OLPC), a non-profit 501(c)(3) organization.

The subnotebooks were designed for sale to government-education systems which then would give each primary school child their own laptop. Pricing was set to start at US$188 in 2006, with a stated goal to reach the $100 mark in 2008 and the 50-dollar mark by 2010.[8] When offered for sale in the Give One Get One campaigns of Q4 2006 and Q4 2007, the laptop was sold at $199.[9]

The rugged, low-power computers use flash memory instead of a hard disk drive (HDD), and come with a pre-installed operating system derived from Fedora Linux, with the Sugar graphical user interface (GUI).[10] Mobile ad hoc networking via 802.11s Wi-Fi mesh networking, to allow many machines to share Internet access as long as at least one of them could connect to an access point, was initially announced, but quickly abandoned after proving unreliable.[11]

The latest version of the OLPC XO is the XO-4 Touch,[12] was introduced in 2012.


Main article: One Laptop per Child

OLPC XO-1 original design proposal

The first early prototype was unveiled by the project's founder Nicholas Negroponte and then-United Nations Secretary-General Kofi Annan on November 16, 2005, at the World Summit on the Information Society (WSIS) in Tunis, Tunisia.[13] The device shown was a rough prototype using a standard development board. Negroponte estimated that the screen alone required three more months of development.[citation needed] The first working prototype was demonstrated at the project's Country Task Force Meeting on May 23, 2006.[citation needed]

Steve Jobs had offered Mac OS X free of charge for use in the laptop, but according to Seymour Papert, a professor emeritus at MIT who is one of the initiative's founders, the designers wanted an operating system that can be tinkered with: "We declined because it's not open source."[14] Therefore, Linux was chosen.

In 2006, there was a major controversy because Microsoft had suddenly developed an interest in the XO project and wanted the formerly open source effort to run Windows. Negroponte agreed to provide engineer assistance to Microsoft to facilitate their efforts. During this time, the project mission statement changed to remove mentions of "open source". A number of developers, such as Ivan Krstić and Walter Bender, resigned because of these changes in strategy.[15][16][17] The version of Windows that ran on the XO was Windows XP.[18]

Approximately 400 developer boards (Alpha-1) were distributed in mid-2006; 875 working prototypes (Beta 1) were delivered in late 2006; 2400 Beta-2 machines were distributed at the end of February 2007;[19] full-scale production started November 6, 2007.[20] Quanta Computer, the project's contract manufacturer, said in February 2007 that it had confirmed orders for one million units. Quanta indicated that it could ship five million to ten million units that year because seven nations had committed to buy the XO-1 for their schoolchildren: Argentina, Brazil, Libya, Nigeria, Rwanda, Thailand, and Uruguay.[21] Quanta plans to offer machines very similar to the XO-1 on the open market.[22]

The One Laptop Per Child project originally stated that a consumer version of the XO laptop was not planned.[23] In 2007, the project established a website,, for outright donations and for a "Give 1 Get 1" offer valid (but only to the United States, its territories, and Canadian addresses) from November 12, 2007 until December 31, 2007.[24] For each computer purchased at a cost of $399, an XO is also sent to a child in a developing nation.[24] OLPC again restarted the G1G1 program through in November 2008, but has since stopped as of December 2008 or 2009.[25]

On May 20, 2008, OLPC announced the next generation of XO, OLPC XO-2[26] which was thereafter cancelled in favor of the tablet-like designed XO-3. In late 2008, the New York City Department of Education began a project to purchase large numbers of XO computers for use by schoolchildren.[27]

The design received the Community category award of the 2007 Index: Award.[28][29]

In 2008 the XO was awarded London's Design Museum "Design of the Year", plus two gold, one silver, and one bronze award at the Industrial Design Society of America's International Design Excellence Awards (IDEAs).[7]


OLPC XO-1 laptop in e-book mode

The XO-1 is designed to be low-cost, small, durable, and efficient. It is shipped with a slimmed-down version of Fedora Linux and a custom GUI named Sugar that is intended to help young children collaborate. The XO-1 includes a video camera, a microphone, long-range Wi-Fi, and a hybrid stylus and touchpad. Along with a standard plug-in power supply, human and solar power sources are available, allowing operation far from a commercial power grid. Mary Lou Jepsen has listed the design goals of the device as follows:[30]

In keeping with its goals of robustness and low power use, the design of the laptop intentionally omits all motor-driven moving parts; it has no hard disk drive, optical (compact disc (CD) or Digital Versatile Disc DVD) media, floppy disk drive, or fan (the device is passively cooled). No Serial ATA interface is needed due to the lack of hard drive. Storage is via an internal SD card slot.[31] There is also no PC card slot, although Universal Serial Bus (USB) ports are included.

A built-in hand-crank generator was part of the notebook in the original design; however, it is now an optional clamp-on peripheral.[32]


This section is in list format but may read better as prose. You can help by converting this section, if appropriate. Editing help is available. (June 2015)
Production version (4th generation): functional survey
XO-1 motherboard
Marvell's IEEE 802.11 chipset runs an RTOS on an ARM9 and interfaces over a shim with the actual operating system
Rotatable display cover of the XO
XO-1 clamp charger

The latest version of the OLPC XO is the XO-4 Touch.[12]


Comparison of the XO-1 display (left) with a typical liquid crystal display (LCD). The images show 1×1 mm of each screen. A typical LCD addresses groups of 3 locations as pixels. The OLPC XO LCD addresses each location as a separate pixel
A transflective Pixel Qi screen installed in an OLPC XO laptop operating in reflective mode, note that the screen is in grey scale mode and is not retro illuminated

The first-generation OLPC laptops have a novel low-cost liquid crystal display (LCD).

The electronic visual display is the costliest component in most laptops. In April 2005, Negroponte hired Mary Lou Jepsen, who was interviewing to join the Media Arts and Sciences faculty at the MIT Media Lab in September 2008,[33] as OLPC Chief Technology Officer. Jepsen developed a new display for the first-generation OLPC laptop, inspired by the design of small LCDs used in portable DVD players, which she estimated would cost about $35. In the OLPC XO-1, the screen is estimated to be the second most costly component, after the central processing unit (CPU) and chipset.[34]

Jepsen has described the removal of the filters that color the RGB subpixels as the critical design innovation in the new LCD. Instead of using subtractive color filters, the display uses a plastic diffraction grating and lenses on the rear of the LCD to illuminate each pixel.[dubiousdiscuss] This grating pattern is stamped using the same technology used to make DVDs. The grating splits the light from the white backlight into a spectrum. The red, green, and blue components are diffracted into the correct positions to illuminate the corresponding pixel with R, G or B. This innovation results in a much brighter display for a given amount of backlight illumination: while the color filters in a regular display typically absorb 85% of the light that hits them, this display absorbs little of that light. Most LCD screens at the time used cold cathode fluorescent lamp backlights which were fragile, difficult or impossible to repair, required a high voltage power supply, were relatively power-hungry, and accounted for 50% of the screens' cost (sometimes 60%). The light-emitting diode (LED) backlight in the XO-1 is easily replaceable, rugged, and low-cost.[35][36]

The remainder of the LCD uses extant display technology and can be made using extant manufacturing equipment. Even the masks can be made using combinations of extant materials and processes.

When lit primarily from the rear with the white LED backlight, the display shows a color image composed of both RGB and grayscale information.[37] When lit primarily from the front by ambient light, for example from the sun, the display shows a monochromatic (black and white) image composed of just the grayscale information.

"Mode" change occurs by varying the relative amounts backlight and ambient light. With more backlight, a higher chrominance is available and a color image display is seen. As ambient light levels, such as sunlight, exceed the backlight, a grayscale display is seen; this can be useful when reading e-books for an extended time in bright light such as sunlight. The backlight brightness can also be adjusted to vary the level of color seen in the display and to conserve battery power.

In color mode (when lit primarily from the rear), the display does not use the common RGB pixel geometry for liquid crystal computer displays, in which each pixel contains three tall thin rectangles of the primary colors. Instead, the XO-1 display provides one color for each pixel. The colors align along diagonals that run from upper-right to lower left (see diagram on the right). To reduce the color artifacts caused by this pixel geometry, the color component of the image is blurred by the display controller as the image is sent to the screen. Despite the color blurring, the display still has high resolution for its physical size; normal displays as of February 2007 put about 588(H) × 441(V) to 882(H) × 662(V) pixels in this amount of physical area[citation needed] and support subpixel rendering for slightly higher perceived resolution. A Philips Research study measured the XO-1 display's perceived color resolution as effectively 984(H) × 738(V).[38][39][40] A conventional liquid crystal display with the same number of green pixels (green carries most brightness or luminance information for human eyes) as the OLPC XO-1 would be 693 × 520.[citation needed] Unlike a standard RGB LCD, resolution of the XO-1 display varies with angle. Resolution is greatest from upper-right to lower left, and lowest from upper-left to lower-right. Images which approach or exceed this resolution will lose detail and gain color artifacts. The display gains resolution when in bright light; this comes at the expense of color (as the backlight is overpowered) and color resolution can never reach the full 200 dpi sharpness of grayscale mode because of the blur which is applied to images in color mode.


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XO-1 multi-battery charger
Selfmade laptop charging station in classroom

The laptop design specification goals are about 2 W of power consumed during normal use, far less than the 10 W to 45 W of conventional laptops.[19] With build 656, power use is between 5 and 8 watts measured on G1G1 laptop. Future software builds are expected to meet the 2-watt target.

In e-book mode (XO 1.5), all hardware sub-systems except the monochrome dual-touch display are powered down. When the user moves to a different page, the other systems wake up, render the new page on the display, and then go back to sleep. Power use in this e-book mode is estimated to be 0.3 to 0.8 W. The XO 2.0 is planned to consume even less power than earlier versions, less than 1.0 W in full color mode.

Power options include batteries, solar power panels, and human-powered generators, which make the XO self-powered equipment. 10 batteries at once can be charged from the school building power in the XO multi-battery charger. The low power use, combined with these power options are useful in many countries that lack a power infrastructure.


This article's factual accuracy may be compromised due to out-of-date information. Please help update this article to reflect recent events or newly available information. (October 2009)
XO-1 Internet access through wireless mesh networking
An "active antenna" for extending network reach

IEEE 802.11b support will be provided using a Wi-Fi "Extended Range" chip set. Jepsen has said the wireless chip set will be run at a low bit rate, 2 Mbit/s maximum rather than the usual higher speed 5.5 Mbit/s or 11 Mbit/s to minimize power use. The conventional IEEE 802.11b system only handles traffic within a local cloud of wireless devices in a manner similar to an Ethernet network. Each node transmits and receives its own data, but it does not route packets between two nodes that cannot communicate directly. The OLPC laptop will use IEEE 802.11s to form the wireless mesh network.

Whenever the laptop is powered on it can participate in a mobile ad hoc network (MANET) with each node operating in a peer-to-peer fashion with other laptops it can hear, forwarding packets across the cloud[when?]. If a computer in the cloud has access to the Internet—either directly or indirectly—then all computers in the cloud are able to share that access. The data rate across this network will not be high; however, similar networks, such as the store and forward Motoman project[44] have supported email services to 1000 schoolchildren in Cambodia, according to Negroponte. The data rate should be sufficient for asynchronous network applications (such as email) to communicate outside the cloud; interactive uses, such as web browsing, or high-bandwidth applications, such as video streaming should be possible inside the cloud. The IP assignment for the meshed network is intended to be automatically configured, so no server administrator or an administration of IP addresses is needed.

Building a MANET is still untested under the OLPC's current configuration and hardware environment. Although one goal of the laptop is that all of its software be open source, the source code for this routing protocol is currently closed source. While there are open-source alternatives such as OLSR or B.A.T.M.A.N., none of these options is yet available running at the data-link layer (Layer 2) on the Wi-Fi subsystem's co-processor; this is critical to OLPC's power efficiency scheme. Whether Marvell Technology Group, the producer of the wireless chip set and owner of the current meshing protocol software, will make the firmware open source is still an unanswered question. As of 2011, it has not done so.


Yves Behar is the chief designer of the present XO shell. The shell of the laptop is resistant to dirt and moisture, and is constructed with 2 mm thick plastic (50% thicker than typical laptops). It contains a pivoting, reversible display, movable rubber Wi-Fi antennas, and a sealed rubber-membrane keyboard.

Input and ports

Close-up of the OLPC keyboard

More than twenty different keyboards have been laid out, to suit local needs to match the standard keyboard for the country in which a laptop is intended. Around half of these have been manufactured for prototype machines.[45][46] There are parts of the world which do not have a standard keyboard representing their language. As Negroponte states this is "because there's no real commercial interest in making a keyboard".[47] One example of where the OLPC has bridged this gap is in creating an Amharic keyboard[48] for Ethiopia. For several languages, the keyboard is the first ever created for that language.[11]

Negroponte has demanded that the keyboard not contain a caps lock key, which frees up keyboard space for new keys such as a future "view source" key.[49]

Beneath the keyboard was a large area that resembled a very wide touchpad. The capacitive portion of the mousepad was an Alps GlidePoint touchpad,[50][51] which was in the central third of the sensor and could be used with a finger. The full width was a resistive sensor which, though never supported by software, was intended to be used with a stylus. This unusual feature was eliminated in the CL1A hardware revision because it suffered from erratic pointer motion. Alps Electronics provided both the capacitive and resistive components of the mousepad.[50]

Release history

The first XO prototype, displayed in 2005, had a built-in hand-crank generator for charging the battery. The XO-1 beta, released in early 2007, used a separate hand-crank generator.[citation needed]

The XO-1 was released in late 2007.[52][53]

The Oberon subsystem in UnixAos on a XO-1.5.

The XO 1.5 was released in early 2010.[55]

The XO 1.75 began development in 2010,[56][57] with full production starting in February 2012.[58]

The XO 2, previously scheduled for release in 2010, was canceled in favor of XO 3. With a price target $75, it had an elegant, lighter, folding dual touch-screen design. The hardware would have been open-source and sold by various manufacturers. A choice of operating system (Windows XP or Linux) was intended outside the United States. Its $150 price target in the United States includes two computers, one donated.[60]

The OLPC XO-3 was scheduled for release in late 2012. It was canceled in favor of the XO-4. It featured one solid color multi-touch screen design, and a solar panel in the cover or carrying case.

The XO 4 is a refresh of the XO 1 to 1.75 with a later ARM CPU and an optional touch screen. This model will not be available for consumer sales. There is a mini HDMI port to allow connecting to a display.[12]

The XO Tablet was designed by third-party Vivitar, rather than OLPC, and based on the Android platform[61][62] whereas all previous XO models were based on Sugar running on top of Fedora. It is commercially available[63][64] and has been used in OLPC projects.[65]


See also: Sugar (desktop environment)

Mock-up of the "neighborhood view" showing children collaborating on various tasks, within the mesh network. By clicking on the icon, communication by Wi-Fi is activated

Countries are expected to remove and add software to best adapt the laptop to the local laws and educational needs. As supplied by OLPC, all of the software on the laptop will be free and open source.[49] All core software is intended to be localized to the languages of the target countries.[66] The underlying software[67] includes:

The laptop uses the Sugar graphical user interface, written in Python, on top of the X Window System and the Matchbox window manager.[69] This interface is not based on the typical desktop metaphor but presents an iconic view of programs and documents and a map-like view of nearby connected users. The current active program is displayed in full-screen mode.[19] Much of the core Sugar interface uses icons, bypassing localization issues. Sugar is also defined as having no folders present in the UI.

Activity, home, friends and neighborhood software levels

Jim Gettys, responsible for the laptops' system software, has called for a re-education of programmers, saying that many applications use too much memory or even leak memory. "There seems to be a common fallacy among programmers that using memory is good: on current hardware it is often much faster to recompute values than to have to reference memory to get a precomputed value. A full cache miss can be hundreds of cycles, and hundreds of times the power use of an instruction that hits in the first level cache."[54]

On August 4, 2006, the Wikimedia Foundation announced that static copies of selected Wikipedia articles would be included on the laptops. Jimmy Wales, chair of the Wikimedia Foundation, said that "OLPC's mission goes hand in hand with our goal of distributing encyclopedic knowledge, free of charge, to every person in the world. Not everybody in the world has access to a broadband connection."[71] Negroponte had earlier suggested he would like to see Wikipedia on the laptop. Wales feels that Wikipedia is one of the "killer apps" for this device.[72]

Don Hopkins announced that he is creating a free and open source port of the game SimCity to the OLPC with the blessing of Will Wright and Electronic Arts, and demonstrated SimCity running on the OLPC at the Game Developer's Conference in March 2007.[73] The free and open source SimCity plans were confirmed at the same conference by SJ Klein, director of content for the OLPC, who also asked game developers to create "frameworks and scripting environments—tools with which children themselves could create their own content."[74][75]

The laptop's security architecture, known as Bitfrost, was publicly introduced in February 2007. No passwords will be required for ordinary use of the machine. Programs are assigned certain bundles of rights at install time which govern their access to resources; users can later add more rights. Optionally, the laptops can be configured to request leases from a OLPC XS central server and to stop working when the leases expire; this is designed as a theft-prevention mechanism.

The pre-8.20 software versions were criticized for bad wireless connectivity and other minor issues.[76]


The XO-1 is nicknamed ceibalita in Uruguay after the Ceibal project.[77]

Reception and reviews

The hand-crank system for powering the laptop was abandoned by designers shortly after it was announced, and the "mesh" internet-sharing approach performed poorly and was then dropped.[11] Bill Gates of Microsoft criticized the screen quality.[11]

Some critics of the program would have preferred less money being spent on technology and more money being spent on clean water and "real schools".[11] Some supporters worried about the lack of plans for teaching students. The program was based on constructionism, which is the idea that, if they had the tools, the kids would largely figure out how to do things on their own.[11] Others wanted children to learn the Microsoft Windows operating system, rather than OLPC's lightweight Linux derivative, on the belief that the children would use Microsoft Windows in their careers.[11] Intel's Classmate PC used Microsoft Windows and sold for US$200 to 400.[11]

The project was known as "the $100 laptop", but it originally cost $130 for a bare-bones laptop, and then the price rose to $180 in the next revision.[11] The solid-state alternative to a hard drive was sturdy, which meant that the laptop could be dropped with a lower risk of breaking—although more laptops were broken than expected—but it was costly, so the machines had limited storage capacity.[11]

See also


  1. ^ Lanxon, Nate. "Netbooks: Credit OLPC, not just Asus – Nate Lanxon, MP3 & Digital Music Editor – Technology Blog at". Archived from the original on 2009-02-02. Retrieved 2009-01-17.
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  3. ^ Papert, Seymour (1993). The Children's Machine. BasicBooks. ISBN 0-465-01830-0.
  4. ^ "Negropontism: A CM1 to 2B1 Backstory".
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  6. ^ "Vision: Children in the developing world are inadequately educated". Retrieved 2008-01-25.
  7. ^ a b Huppatz, D.J. (2011). "Roland Barthes, Mythologies". Design and Culture. 3 (1): 85–100. doi:10.2752/175470810X12863771378833. S2CID 144391627.
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  9. ^ "One Laptop per Child: Ways to Give". Retrieved 2009-06-14.
  10. ^ "OLPC's Software". The OLPC Wiki. One Laptop per Child. Retrieved 2007-12-24.
  11. ^ a b c d e f g h i j Robertson, Adi (16 April 2018). "OLPC's $100 laptop was going to change the world – then it all went wrong". The Verge. Retrieved 2018-04-23.
  12. ^ a b c "XO-4 Touch". OLPC 2008-05-27. Retrieved 2013-08-16.
  13. ^ UN debut for $100 laptop for poor. BBC, 17 November 2005.
  14. ^ Stecklow, Steve (November 14, 2005). "The $100 Laptop Moves Closer to Reality". Wall Street Journal.
  15. ^ Microsoft Windows XP on the Children's Machine XO?! (5 Dec 2006). "Microsoft Windows XP on the Children's Machine XO?!". OLPC News. Retrieved 2013-08-16.
  16. ^ Fildes, Jonathan (May 16, 2008). "'$100 Laptop' Platform Moves On". BBC News.
  17. ^ "XP on XO: Negroponte has lost his bearings". ZDNet. 2008-05-16. Retrieved 2013-08-16.
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  20. ^ Jan Melin (November 7, 2007). 100-dollarsdatorn masstillverkas. NYTeknik. Retrieved on December 24, 2007.
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  30. ^ "A conversation with Mary Lou Jepsen", ACM Queue journal, November 1, 2007
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  70. ^ Turtle Art is a visual programming language that, like Logo, manipulates an on-screen turtle.
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  73. ^ "SimCity for OLPC". 2007-03-08.
  74. ^ GDC: SJ Klein Asks For Serious OLPC Content, Gamasutra Industry News, 6 March 2007
  75. ^ Electronic Arts. "EA Donates Original City-Building Game, SIMCITY, To One Laptop Per Child Initiative". Retrieved 2008-01-25.
  76. ^ Bender, Walter (16 December 2008). "Criticism and Rebuttal on Sugar User Interface". OLPC News. Retrieved 2013-08-16.
  77. ^ La última ceibalita, Portal 180, October 14, 2009 (in Spanish) Archived October 18, 2009, at the Wayback Machine