4X is a genre of strategy-based video and board games in which players control an empire and "explore, expand, exploit, and exterminate". The term was coined by Alan Emrich in his September 1993 preview of Master of Orion for Computer Gaming World.[1] Since then, others have adopted the term to describe games of similar scope and design.

4X computer games are noted for their deep, complex gameplay. Emphasis is placed upon economic and technological development, as well as a range of non-military routes to supremacy. Games can take a long time to complete since the amount of micromanagement needed to sustain an empire increases as the empire grows. 4X games are sometimes criticized for becoming tedious for these reasons, and several games have attempted to address these concerns by limiting micromanagement, with varying degrees of success.

The earliest 4X games borrowed ideas from board games and 1970s text-based computer games. The first 4X computer games were turn-based, but real-time 4X games are not uncommon. Many 4X computer games were published in the mid-1990s, but were later outsold by other types of strategy games. Sid Meier's Civilization is an important example from this formative era, and popularized the level of detail that later became a staple of the genre. In the new millennium, several 4X releases have become critically and commercially successful.

In the board (and card) game domain, 4X is less of a distinct genre, in part because of the practical constraints of components and playing time. The Civilization board game that gave rise to Sid Meier's Civilization computer game, for instance, has no exploration and no extermination. Unless extermination is targeted at non-player entities, it tends to be either nearly impossible (because of play balance mechanisms, since player elimination is usually considered an undesirable feature) or certainly unachievable (because victory conditions are triggered before extermination can be completed) in board games.

Detailed empire management, seen here in Freeciv, is a central aspect of 4X strategy games.


4X computer games such as Master of Orion II let empires explore the map, expanding by founding new colonies and exploiting their resources. The game can be won either by becoming an elected leader of the galaxy or by exterminating all opponents.

The term "4X" originates from a 1993 preview of Master of Orion in Computer Gaming World by Alan Emrich, in which he rated the game "XXXX" as a pun on the XXX rating for pornography. The four Xs were an abbreviation for "EXplore, EXpand, EXploit and EXterminate".[1] By February 1994 another author in the magazine stated that Command Adventures: Starship "only pays lip service to the four X's",[2] and other game commentators adopted the "4X" label to describe a game genre with specific gameplay conventions:[3][4][5]

  • Explore means players send scouts across a map to reveal surrounding territories.
  • Expand means players claim new territory by creating new settlements, or sometimes by extending the influence of existing settlements.
  • Exploit means players gather and use resources in areas they control, and improve the efficiency of that usage.
  • Exterminate means attacking and eliminating rival players. Since in some games all territory is eventually claimed, eliminating a rival's presence may be the only way to achieve further expansion.

These four elements of gameplay have been described as the four phases of a 4X computer game session.[6] These phases often overlap with each other and vary in length depending on the game design. For example, the Space Empires series and Galactic Civilizations II: Dark Avatar have a long expansion phase, because players must make large investments in research to explore and expand into every area.[7][8][9]

Difficulties in definition

While many computer strategy games arguably contain a similar "explore, expand, exploit, exterminate" cycle,[10] game journalists, developers and enthusiasts generally apply "4X" to a more specific class of games,[10] and contrast 4X games with other strategy games such as Command & Conquer.[11][12] Hence, writers have tried to show how 4X games are defined by more than just having each of the four Xs. Computer gaming sites have stated that 4X games are distinguished by their greater complexity and scale,[13] and their intricate use of diplomacy beyond the standard "friend or foe" seen in other strategy games.[10][11][14] Reviewers have also stated that 4X games feature a range of diplomatic options,[15][16][17][18] and that they are well known for their large detailed empires and complex gameplay.[17][19] In particular, 4X games offer detailed control over an empire's economy, while other computer strategy games simplify this in favor of combat-focused gameplay.[13]

Game design

4X computer games are a subgenre of strategy games,[3][4][5] and include both turn-based and real-time strategy titles.[20][21] The gameplay involves building an empire,[19] which takes place in a setting such as Earth,[22] a fantasy world, or in space.[6] Each player takes control of a different civilization or race with unique characteristics and strengths. Most 4X games represent these racial differences with a collection of economic and military bonuses.

Research and technology

One part of Freeciv's technology tree. Note the complex dependencies between technologies.
Freeciv-2.1.8 technology tree
One part of Freeciv's technology tree. Note the complex dependencies between technologies.
Freeciv-2.1.8 technology tree

4X games typically feature a technology tree, which represents a series of advancements that players can unlock to gain new units, buildings, and other capabilities. Technology trees in 4X games are typically larger than in other strategy games, featuring a larger selection of choices.[10][23] Empires must generate research resources and invest them in new technology.[24] In 4X games, the main prerequisite for researching an advanced technology is knowledge of earlier technology.[11] This is in contrast to non-4X real-time strategy games, where technological progress is achieved by building structures that grant access to more advanced structures and units.[25]

Research is important in 4X games because technological progress is an engine for conquest.[26] Battles are often won by superior military technology or greater numbers, with battle tactics playing a smaller part.[27][28] In contrast, military upgrades in non-4X games are sometimes small enough that technologically basic units remain important throughout the game.[29]


Combat is an important part of 4X gameplay, because 4X games allow a player to win by exterminating all rival players, or by conquering a threshold amount of the game's universe.[30] Some 4X games, such as Galactic Civilizations, resolve battles automatically, whenever two units from warring sides meet.[31] This is in contrast to other 4X games, such as Master of Orion, that allow players to manage battles on a tactical battle screen.[31][32] Even in 4X games with more detailed control over battles, victory is usually determined by superior numbers and technology, with battle tactics playing a smaller part.[27][28] 4X games differ from other combat-focused strategy games by putting more emphasis on research and economics.[1][13] Researching new technology will grant access to new combat units. Some 4X games even allow players to research different unit components. This is more typical of space 4X games, where players may assemble a ship from a variety of engines, shields, and weaponry.[31]

Peaceful competition

4X games allow rival players to engage in diplomacy.[15][16][17][18] While some strategy games may offer shared victory and team play, diplomatic relations tend to be restricted to a binary choice between an ally or enemy. 4X games often allow more complex diplomatic relations between competitors who are not on the same team.[10][11][14] Aside from making allies and enemies, players are also able to trade resources and information with rivals.[21]

In addition to victory through conquest, 4X games often offer peaceful victory conditions or goals that involve no extermination of rival players (although war may still be a necessary by-product of reaching said goal).[13] For example, a 4X game may offer victory to a player who achieves a certain score or the highest score after a certain number of turns.[33] Many 4X games award victory to the first player to master an advanced technology, accumulate a large amount of culture, or complete an awe-inspiring achievement.[31] Several 4X games award "diplomatic victory" to anyone who can win an election decided by their rival players,[34][35] or maintain peace for a specified number of turns.[33] Galactic Civilizations has a diplomatic victory which involves having alliances with at least 4 factions, with no factions outside of one's alliance; there are two ways to accomplish this: ally with all factions, or ally with at least the minimum number of factions and destroy the rest.


4X games are known for their complex gameplay[17][18] and strategic depth.[19][20][36] Gameplay usually takes priority over elaborate graphics.[23][37] Whereas other strategy games focus on combat, 4X games also offer more detailed control over diplomacy, economics, and research;[1][13] creating opportunities for diverse strategies.[38] This also challenges the player to manage several strategies simultaneously, and plan for long-term objectives.[39]

To experience a detailed model of a large empire, 4X games are designed with a complex set of game rules.[17] For example, the player's productivity may be limited by pollution.[40][41] Players may need to balance a budget, such as managing debt,[42] or paying down maintenance costs.[43] 4X games often model political challenges such as civil disorder,[30][40] or a senate that can oust the player's political party or force them to make peace.[40][44]

FreeCol colony screen
FreeCol is typical of 4X games where there is a separate interface for managing each settlement.

Such complexity requires players to manage a larger amount of information than other strategy games.[36] Game designers often organize empire management into different interface screens and modes,[13] such as a separate screen for diplomacy,[45][46] managing individual settlements, and managing battle tactics.[31][32] Sometimes systems are intricate enough to resemble a minigame.[39][47] This is in contrast to most real-time strategy games. Dune II, which arguably established the conventions for the real-time strategy genre, was fundamentally designed to be a "flat interface", with no additional screens.[25]


Since 4X games involve managing a large, detailed empire, game sessions usually last longer than other strategy games.[13] Game sessions may require several hours of play-time, which can be particularly problematic for multiplayer matches.[48] For example, a small-scale game in Sins of a Solar Empire can last for over 12 hours.[17] However, fans of the genre often expect and embrace these long game sessions;[49] Emrich wrote that "when the various parts are properly designed, other X's seem to follow. Words like EXcite, EXperiment and EXcuses (to one's significant others)".[1] Turn-based 4X games typically divide these sessions into hundreds of turns of gameplay.[39][50]

Because of repetitive actions and long-playing times, 4X games have been criticized for excessive micromanagement. In early stages of a game this is usually not a problem, but later in a game directing an empire's numerous settlements can demand several minutes to play a single turn. This increases playing-times, which are a particular burden in multiplayer games.[48] 4X games began to offer AI governors that automate the micromanagement of a colony's build orders, but players criticized these governors for making poor decisions. In response, developers have tried other approaches to reduce micromanagement,[51] and some approaches have been more well received than others. Commentators generally agree that Galactic Civilizations succeeds, which GamingNexus.com attributes to the game's use of programmable governors.[52] Sins of a Solar Empire was designed to reduce the incentives for micromanagement,[53] and reviewers found that the game's interface made empire management more elegant.[18][36] On the other hand, Master of Orion III reduced micromanagement by limiting complete player control over their empire.[54][55]



Sid Meier cropped
Sid Meier, the creator of the Civilization series of 4X games

Early 4X games were influenced by board games and text-based computer games from the 1970s.[56] Cosmic Balance II, Andromeda Conquest and Reach for the Stars were published in 1983, and are now seen retrospectively as 4X games. Although Andromeda Conquest was only a simple game of empire expansion, Reach for the Stars introduced the relationship between economic growth, technological progress, and conquest.[26]

Prior to Sid Meier, Robert T. Smith[57] created the precursor of all 4X strategy video games: Armada 2525 (followed up by a version with enhanced graphics: Armada 2525 Deluxe). However, due to the financial problems of the publishing company Interstel Corporation,[58] Armada 2525 never got enough marketing and attention from gamers. Future 4X space strategy games such as Master of Orion would go on to adopt the gameplay and concepts found in Armada 2525. Armada 2526, the spiritual successor to Armada 2525 was released by Ntronium Games in 2009, 19 years after the release of the original in 1990.

In 1991, Sid Meier released Civilization and popularized the level of detail that has become common in the genre.[59] Sid Meier's Civilization was influenced by board games such as Risk and the Avalon Hill board game also called Civilization. A notable similarity between the Civilization computer game and board game is the importance of diplomacy and technological advancement. Sid Meier's Civilization was also influenced by personal computer games such as the city management game SimCity and the wargame Empire.[60] Civilization became widely successful and influenced many 4X games to come;[59] Computer Gaming World compared its importance to computer gaming to that of the wheel.[61]

In 1991, two highly influential space games were released. VGA Planets was released for the PC, while Spaceward Ho! was released on the Macintosh. Although 4X space games were ultimately more influenced by the complexity of VGA Planets, Spaceward Ho! earned praise for its relatively simple yet challenging game design.[62] Spaceward Ho! is notable for its similarity to the 1993 game Master of Orion,[1][63] with its simple yet deep gameplay.[32] Master of Orion also drew upon earlier 4X games such as Reach for the Stars,[1][64] and is considered a classic game that set a new standard for the genre.[32][48] In a preview of Master of Orion, Emrich coined the term "XXXX" to describe the emerging genre.[1] Eventually, the "4X" label was adopted by the game industry, and is now applied to several earlier game releases.[65]


Following the success of Civilization and Master of Orion, other developers began releasing their own 4X games. In 1994, Stardock launched its first version of the Galactic Civilizations series for OS/2,[66] and the long-standing Space Empires series began as shareware. Ascendancy and Stars! were released in 1995, and both continued the genre's emphasis on strategic depth and empire management.[65] Meanwhile, the Civilization[67] and Master of Orion[68] franchises expanded their market with versions for the Macintosh. Sid Meier's team also produced Colonization in 1994 and Civilization II in 1996,[69] while Simtex released Master of Orion in 1993, Master of Magic in 1994 and Master of Orion II in 1996.[70]

By the late 1990s, real-time strategy games began outselling turn-based games.[71] As they surged in popularity, major 4X developers fell into difficulties. Sid Meier's Firaxis Games released Sid Meier's Alpha Centauri in 1999 to critical acclaim, but the game fell short of commercial expectations.[72] Civilization III encountered development problems followed by a rushed release in 2001.[73] Despite the excitement over Master of Orion III, its release in 2003 was met with criticism for its lack of player control, poor interface, and weak AI.[55] Game publishers eventually became risk-averse to financing the development of 4X games.[19]

Real-time hybrid 4X

Eventually real-time 4X games were released, such as Imperium Galactica in 1997,[20] Starships Unlimited in 2001,[21] and Sword of the Stars in 2006, featuring a combination of turn-based strategy and real-time tactical combat. The blend of 4X and real-time strategy gameplay led Ironclad Games to market their 2008 release Sins of a Solar Empire as a "RT4X" game.[4][74] This combination of features earned the game a mention as one of the top games from 2008, including GameSpot's award for best strategy game, and IGN's award for best PC game.[75][76][77][78]

Cross-fertilization between board games and video games continued. For example, some aspects of Master of Orion III were drawn from the first edition of the board game Twilight Imperium.[79] Even Sins of a Solar Empire was inspired by the idea of adapting the board game Buck Rogers Battle for the 25th Century into a real-time video game.[80] Going in the opposite direction, Eagle Games made a board game adaptation of Sid Meier's Civilization in 2002, completely different from the board game that had inspired the computer game in the first place.[81]

Recent history

In 2003, Stardock released a remake of Galactic Civilizations, which was praised by reviewers who saw the game as a replacement for the Master of Orion series.[82][83] In 2004 the Creative Assembly released the critically acclaimed Rome: Total War, which has spawned many sequels. Civilization IV was released at the end of 2005 and was considered the PC game of the year according to several reviewers, including GameSpot and GameSpy.[84] It is now considered one of the greatest computer games in history, having been ranked the second-best PC game of all time by IGN.[85] By 2008, the Civilization series had sold over eight million copies,[86] followed the release of Civilization Revolution for game consoles soon after,[87] Civilization V in 2010[88] and Civilization VI in 2016. Meanwhile, Stardock released Galactic Civilizations II, which was considered the sixth-best PC game of 2006 by GameSpy.[19] Additionally, French developer Amplitude Studios released both Endless Space and Endless Legend. These successes have led Stardock's Brad Wardell to assert that 4X games have excellent growth potential, particularly among less hardcore players.[89] This is in addition to the loyal base of 4X gamers who have supported free software releases such as Freeciv,[90] FreeCol,[91] Freeorion, Golden Age of Civilizations,[92] and C-evo.[93]

See also


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Army Air Corps (United Kingdom)

The Army Air Corps (AAC) is a component of the British Army, first formed in 1942 during the Second World War by grouping the various airborne units of the British Army (which are no longer part of the AAC). Today, there are eight regiments (seven Regular Army and one Reserve) of the AAC as well as four Independent Flights and two Independent Squadrons deployed in support of British Army operations across the world. They are located in Britain, Brunei, Canada, and Germany. Some AAC squadrons provide the air assault elements of 16 Air Assault Brigade through Joint Helicopter Command.

Boiling point

The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.

The boiling point of a liquid varies depending upon the surrounding environmental pressure. A liquid in a partial vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high pressure has a higher boiling point than when that liquid is at atmospheric pressure. For example, water boils at 100 °C (212 °F) at sea level, but at 93.4 °C (200.1 °F) at 1,905 metres (6,250 ft) altitude. For a given pressure, different liquids will boil at different temperatures.

The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level, 1 atmosphere. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and allow bubbles of vapor to form inside the bulk of the liquid. The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of 1 bar.The heat of vaporization is the energy required to transform a given quantity (a mol, kg, pound, etc.) of a substance from a liquid into a gas at a given pressure (often atmospheric pressure).

Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation. Evaporation is a surface phenomenon in which molecules located near the liquid's edge, not contained by enough liquid pressure on that side, escape into the surroundings as vapor. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, resulting in the formation of vapor bubbles within the liquid.

Degree of a polynomial

The degree of a polynomial is the highest degree of its monomials (individual terms) with non-zero coefficients. The degree of a term is the sum of the exponents of the variables that appear in it, and thus is a non-negative integer. The term order has been used as a synonym of degree but, nowadays, may refer to several other concepts (see order of a polynomial (disambiguation)). For example, the polynomial which can also be expressed as has three terms. The first term has a degree of 5 (the sum of the powers 2 and 3), the second term has a degree of 1, and the last term has a degree of 0. Therefore, the polynomial has a degree of 5, which is the highest degree of any term.

To determine the degree of a polynomial that is not in standard form (for example:), one has to put it first in standard form by expanding the products (by distributivity) and combining the like terms; for example is of degree 1, even though each summand has degree 2. However, this is not needed when the polynomial is expressed as a product of polynomials in standard form, because the degree of a product is the sum of the degrees of the factors.


Four-cross (4X), also called mountain-cross, not to be confused with fourcross, is a relatively new style of mountain bike racing where four bikers race downhill on a prepared, BMX-like track, simply trying to get down first. These bikes are generally either full suspension with 3 to 4 inches of travel, or hardtails, and typically have relatively strong frames. They run a chainguide on front and gears on the back. They have slack head angles, short chainstays and low bottom brackets for good cornering and acceleration. In recent years the tracks raced on have been rougher and less like those used in BMX.

Four-cross was added to the UCI Mountain Bike World Cup and the UCI Mountain Bike & Trials World Championships in 2002, replacing dual slalom. It was removed from the World Cup following the 2011 series. A replacement world series, the 4X Pro Tour, was launched in 2012. As of 2018, the current UCI men's four-cross world champion is Quentin Derbier while the women's world champion is Romana Labounková.

Huawei Honor 4X

The Huawei Honor 4X is a mid-range Android smartphone manufactured by Huawei as part of the Huawei Honor X series. It was released in October 2014, and received generally positive reviews.

Incunabula (video game)

Incunabula is a 1984 computer game by Avalon Hill. It was designed by Steve Estvanik. It is the original computerized version of Avalon Hill's Civilization board game. It was eclipsed by Sid Meier's much more successful Civilization, and its following series, released in 1991.

Kicker (sports magazine)

kicker Sportmagazin (commonly kicker) is Germany's leading sports magazine and is focused primarily on football. The magazine was founded in 1920 by German football pioneer Walther Bensemann and is published twice a week, usually Monday and Thursday, in Nuremberg. The Monday edition sells an average of 240,000 copies, while the Thursday edition has an average circulation of about 220,000 copies (2005 figures).

The magazine also publishes a yearbook, the kicker Almanach. It was first published from 1937 to 1942, and then continuously from 1959 to date.

LG Optimus 4X HD

The LG Optimus 4X HD is a slate, multi-touch smartphone running the Android operating system. Designed and manufactured by LG Electronics. The Optimus 4X HD was the world's first smartphone announced with a quad-core processor along with the HTC One X and the Samsung Galaxy S3 and the fourth phone in the LG Optimus-Android series. LG first introduced the LG Optimus 4X HD at Mobile World Congress. The Optimus 4X HD was launched with Android 4.0 Ice Cream Sandwich. Since April 2013, some variants have had a Jellybean update available.

List of AMD Phenom microprocessors

The AMD Phenom family is a 64-bit microprocessor family from AMD, based on the K10 microarchitecture. It includes the Phenom II X6 hex-core series, Phenom X4 and Phenom II X4 quad-core series, Phenom X3 and Phenom II X3 tri-core series, and Phenom II X2 dual-core series. Other related processors based on the K10 microarchitecture include the Athlon X2 "Kuma" processors, Athlon II processors, and various Opteron, Sempron, and Turion series. The first Phenoms were released in November 2007. An improved second generation was released in December 2008, named Phenom II. Processors with an "e" following the model number (e.g., 910e) are low-power models, typically 45 W for Athlons, 65 W for Phenoms. Processors with a "u" following the model number (e.g., 270u) are ultra-low-power models, typically 20 W for single core chips or 25 W for dual core chips.

Paralympic cross-country skiing

Paralympic cross-county skiing is an adaptation of cross-country skiing for athletes with disabilities. Paralympic cross-country skiing is one of two Nordic skiing disciplines in the Winter Paralympic Games; the other is biathlon. Competition is governed by the International Paralympic Committee (IPC).


QRIO ("Quest for cuRIOsity", originally named Sony Dream Robot or SDR) was a bipedal humanoid entertainment robot developed and marketed (but never sold) by Sony to follow up on the success of its AIBO entertainment robot. QRIO stood approximately 0.6 m (2 feet) tall and weighed 7.3 kg (16 pounds). QRIO's slogan was "Makes life fun, makes you happy!"

On January 26, 2006, on the same day as it announced its discontinuation of AIBO and other products, Sony announced that it would stop development of QRIO. Before it was cancelled, QRIO was reported to be going through numerous development, testing and scalability phases, with the intent of becoming commercially available within three or four years.


Redmi is a sub-brand owned by the Chinese electronics company Xiaomi. It was introduced as a budget smartphone line manufactured by Xiaomi, that was first announced in July 2013. It became a sub-brand, separated from Xiaomi, on January 10, 2019. Redmi phones use the Xiaomi MIUI user interface on top of Android. Models can be divided into regular Redmi phones with screens usually up to 5" and Redmi Note series with displays exceeding 5". Only phone besides these two series is Redmi Pro, first introduced in 2016 with Dual Camera system, USB-C and unique for Xiaomi devices OLED display. Redmi A have been marketed in several Asian and European countries.The most significant difference from other Xiaomi smartphones is that it uses less-expensive components and thus is more cost-effective. In August 2014, The Wall Street Journal reported that in the second quarter of the 2014 fiscal year Xiaomi smartphone shipment rankings in China with a market share of 14%. Redmi sales were attributed as a contributing factor toward this gain in shipment rankings.

Saab 9-4X

The Saab 9-4X is a compact luxury crossover SUV that was introduced at the 2010 LA Auto Show. It is based on the all-wheel-drive GM Theta Premium platform, which also forms the basis for the Cadillac SRX. Production of the 9-4X began in 2011 at General Motors' Ramos Arizpe Assembly in Mexico, but stopped before the end of that year due to the bankruptcy of Saab.

Samsung Galaxy A9 (2018)

The Samsung Galaxy A9 (2018) is a midrange Android smartphone produced by Samsung Electronics as part of the Samsung Galaxy A series. It was announced on 11 October 2018 at the 4x fun event in Malaysia, as the successor to the Samsung Galaxy A9 (2016).

The A9 (2018) is the first quad camera smartphone in the world, featuring 4 different cameras on the rear. It features a 6.3 inch Super AMOLED Infinity Display with curved edges similar to the Samsung Galaxy A8 (2018), and support for Dolby Atmos immersive sound technology

Strategy video game

A strategy video game is a video game that focuses on skillful thinking and planning to achieve victory. It emphasizes strategic, tactical, and sometimes logistical challenges. Many games also offer economic challenges and exploration. They are generally categorized into four sub-types, depending on whether the game is turn-based or real-time, and whether the game focuses on strategy or tactics.

UCI Mountain Bike World Cup

The UCI Mountain Bike World Cup is a multi-round mountain bike racing series that is sanctioned by the Union Cycliste Internationale. The first World Cup series – which was composed of cross-country events – was held in 1989. The Downhill World Cup was inaugurated two years later, and the Dual Slalom World Cup was launched in 1998. The dual-slalom format – which involved knock-out heats with two riders on the parallel courses in each heat – evolved into four-cross (with four riders on a single course per heat) in 2002 before being dropped after the 2011 season. Riders win points according to their placing in each event. The reigning series leaders in each class are identified by a special jersey. The UCI Mountain Bike World Cup is broadcast live and globally on Red Bull TV.

The replacement world series for 4X World Cup is the 4X Pro Tour and for XCM World Cup is UCI MTB Marathon series.


The Visual Memory Unit (VMU), also referred to as the Visual Memory System (ビジュアルメモリ, Bijuaru Memori) (VMS) in Japan and Europe, is the primary memory card produced by Sega for the Dreamcast home video game console. The device features a monochrome liquid crystal display (LCD), multi-player gaming capability (via connectors at the top), second screen functionality, a real-time clock, file manager, built-in flash memory, and sound capability. Prior to the launch of the Dreamcast, a special Godzilla edition VMU, preloaded with a virtual pet game, was released on July 30, 1998 in Japan.While its most basic function is as a removable storage device, the VMU may also serve as an auxiliary display during normal gameplay and, through the use of additional software (distributed as extras on Dreamcast GD-ROMs), acts as a handheld game console. Console-like features of the VMU include a screen, speaker, proper directional pad, four action buttons, the ability to connect and interact with other VMUs, and the ability to download additional games. While the standard VMU is white, colors were expanded to include many variations. Japan even saw the release of branded VMUs, such as those by Sonic Team, Capcom and Hello Kitty.


Xconq is an open-source computer strategy game and game engine. First posted to comp.sources.games on 9 July 1987, it is notable as one of the first multi-player games to be released for the X Window System. It was for several years the only turn-based graphical war game available on Unix/X systems.

Xconq is released as free and open-source software under the terms of the GNU General Public License v2.

Xiaomi Redmi Note 4

The Xiaomi Redmi Note 4 is the fourth smartphone of Redmi Note series developed by Xiaomi Inc. It is a part of Xiaomi's budget Redmi smartphone line. It has two variants: The older version sold as Redmi Note 4 is powered by a Deca-core Mediatek MT6797 Helio X20 SOC. The upgraded version, sold both as Redmi Note 4X and Redmi Note 4 (where MTK version was not released) is powered by an Octa-core MSM8953 Qualcomm Snapdragon 625 SOC. The Redmi Note 4 was succeeded by Redmi Note 5.

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