European Union

It provides support for the development, promotion and distribution of European works within Europe and beyond. * The E.U.'

Computer hardware

hardwarepersonal computer hardwaredevice
It can hold and store information both temporarily and permanently, and can be internal or external to a computer, server or any similar computing device. Data storage is a core function and fundamental component of computers. Data is stored by a computer using a variety of media. Hard disk drives are found in virtually all older computers, due to their high capacity and low cost, but solid-state drives are faster and more power efficient, although currently more expensive than hard drives in terms of dollar per gigabyte, so are often found in personal computers built post-2007. Some systems may use a disk array controller for greater performance or reliability.

Open-source software

open sourceopen-sourceopen source software
Some of the "more prominent organizations" involved in OSS development include the Apache Software Foundation, creators of the Apache web server; the Linux Foundation, a nonprofit which employed Linus Torvalds, the creator of the Linux operating system kernel; the Eclipse Foundation, home of the Eclipse software development platform; the Debian Project, creators of the influential Debian GNU/Linux distribution; the Mozilla Foundation, home of the Firefox web browser; and OW2, European-born community developing open source middleware. New organizations tend to have a more sophisticated governance model and their membership is often formed by legal entity members.

Tim Berners-Lee

Sir Tim Berners-LeeBerners-LeeTim-Berners Lee
His software also functioned as an editor (called WorldWideWeb, running on the NeXTSTEP operating system), and the first Web server, CERN HTTPd (short for Hypertext Transfer Protocol daemon). The first website was built at CERN. Despite this being an international organisation hosted by Switzerland, the office that Berners-Lee used was just across the border in France. The website was put online on 6 August 1991 for the first time: It provided an explanation of what the World Wide Web was, and how people could use a browser and set up a web server, as well as how to get started with your own website.


egalitarianequalityeconomic egalitarianism
Roemer attempts to reformulate Marxist analysis to accommodate normative principles of distributive justice, shifting the argument for socialism away from purely technical and materialist reasons to one of distributive justice. Roemer argues that according to the principle of distributive justice, the traditional definition of socialism based on the principle that individual compensation be proportional to the value of the labour one expends in production is inadequate. Roemer concludes that egalitarians must reject socialism as it is classically defined in order for equality to be realized.

Free and open-source software

free and open-sourcefree and open source softwarefree and open source
In the 1970s and early 1980s, some parts of the software industry began using technical measures (such as distributing only binary copies of computer programs) to prevent computer users from being able to use reverse engineering techniques to study and customize software they had paid for. In 1980, the copyright law was extended to computer programs in the United States —previously, computer programs could be considered ideas, procedures, methods, systems, and processes, which are not copyrightable. Early on, closed-source software was uncommon until the mid-1970s to the 1980s, when IBM implemented in 1983 an "object code only" policy, no longer distributing source code.

Gossip protocol

GossipGossip protocolsGossip-based membership protocol
Building low-diameter P2P networks. G. Pandurangan, P. Raghavan, Eli Upfal. In Proceedings of the 42nd Symposium on Foundations of Computer Science (FOCS), 2001. Astrolabe: A Robust and Scalable Technology for Distributed System Monitoring, Management, and Data Mining. Robbert van Renesse, Kenneth Birman and Werner Vogels. ACM Transactions on Computer Systems (TOCS) 21:2, May 2003. Exploiting Semantic Proximity in Peer-to-peer Content Searching. S. Voulgaris, A.-M. Kermarrec, L. Massoulie, M. van Steen. Proc. 10th Int'l Workshop on Future Trends in Distributed Computing Systems (FTDCS 2004), Suzhou, China, May 2004.


malicious softwaremaliciousmalicious code
Infected "zombie computers" can be used to send email spam, to host contraband data such as child pornography, or to engage in distributed denial-of-service attacks as a form of extortion. Programs designed to monitor users' web browsing, display unsolicited advertisements, or redirect affiliate marketing revenues are called spyware. Spyware programs do not spread like viruses; instead they are generally installed by exploiting security holes. They can also be hidden and packaged together with unrelated user-installed software. Ransomware affects an infected computer system in some way, and demands payment to bring it back to its normal state.

Single point of failure

single points of failurecentral point of failurecauses the entire circuit to "open" or stop operating
One would normally deploy a load balancer to ensure high availability for a server cluster at the system level. In a high-availability server cluster, each individual server may attain internal component redundancy by having multiple power supplies, hard drives, and other components. System level redundancy could be obtained by having spare servers waiting to take on the work of another server if it fails. Since a data center is often a support center for other operations such as business logic, it represents a potential SPOF in itself.

Computational trust

trust mechanismstrusted
Rigid authentication mechanisms, such as Public Key Infrastructures (PKIs) or Kerberos have allowed this model to be extended to distributed systems within a few closely collaborating domains or within a single administrative domain. During recent years, computer science has moved from centralised systems to distributed computing. This evolution has several implications for security models, policies and mechanisms needed to protect users’ information and resources in an increasingly interconnected computing infrastructure. Identity-based security mechanisms cannot authorise an operation without authenticating the claiming entity.

Replication (computing)

replicationdata replicationreplicated
In comparison, if any replica can process a request and distribute a new state, the system is using a multi-primary or multi-master scheme. In the latter case, some form of distributed concurrency control must be used, such as a distributed lock manager. Load balancing differs from task replication, since it distributes a load of different computations across machines, and allows a single computation to be dropped in case of failure. Load balancing, however, sometimes uses data replication (especially multi-master replication) internally, to distribute its data among machines. Backup differs from replication in that the saved copy of data remains unchanged for a long period of time.

Publish–subscribe pattern

This is also a design challenge for alternative messaging architectures, such as a client/server system. In a client/server system, when an error logger fails, the system will receive an indication of the error logger (server) failure. However, the client/server system will have to deal with that failure by having redundant logging servers online, or by dynamically spawning fallback logging servers. This adds complexity to the client and server designs, as well as to the client/server architecture as a whole.

Record (computer science)

Rust:. Haskell:. Julia:. Standard ML:. Block (data storage). Composite data type. Cons cell. Data hierarchy. Data structure alignment. Object composition. Row (database). Storage record. Passive data structure. Union type.

Control flow

looploopscontrol structure
For instance, an event-driven program (such as a server) should loop forever, handling events as they occur, only stopping when the process is terminated by an operator. Infinite loops can be implemented using other control flow constructs. Most commonly, in unstructured programming this is jump back up (goto), while in structured programming this is an indefinite loop (while loop) set to never end, either by omitting the condition or explicitly setting it to true, as. Some languages have special constructs for infinite loops, typically by omitting the condition from an indefinite loop. Examples include Ada, Fortran, Go, and Ruby.

Massively multiplayer online game

MMOmassively multiplayer onlinemassively multiplayer
Some recent attempts to build peer-to-peer (P2P) MMOGs have been made. Outback Online may be the first commercial one, however, so far most of the efforts have been academic studies. A P2P MMOG may potentially be more scalable and cheaper to build, but notable issues with P2P MMOGs include security and consistency control, which can be difficult to address given that clients are easily hacked. Some MMOGs such as Vindictus use P2P networking and client-server networking together. In April 2004, the United States Army announced that it was developing a massively multiplayer training simulation called AWE (asymmetric warfare environment).

Cynthia Dwork

DworkC. Dwork
Dwork has also made contributions in cryptography and distributed computing, and is a recipient of the Edsger W. Dijkstra Prize for her early work on the foundations of fault-tolerant systems. Her contributions in cryptography include Nonmalleable Cryptography with Danny Dolev and Moni Naor in 1991, the first lattice-based cryptosystem with Miklós Ajtai in 1997, which was also the first public-key cryptosystem for which breaking a random instance is as hard as solving the hardest instance of the underlying mathematical problem ("worst-case/average-case equivalence").

Cryptographic hash function

cryptographic hashhashhashing
Hashes are used to identify files on peer-to-peer filesharing networks. For example, in an ed2k link, an MD4-variant hash is combined with the file size, providing sufficient information for locating file sources, downloading the file and verifying its contents. Magnet links are another example. Such file hashes are often the top hash of a hash list or a hash tree which allows for additional benefits. One of the main applications of a hash function is to allow the fast look-up of a data in a hash table. Being hash functions of a particular kind, cryptographic hash functions lend themselves well to this application too.


ledgersledger bookaccount book
Distributed ledger, sometimes called a shared ledger, is a consensus of replicated, shared, and synchronized digital data geographically spread across multiple sites, countries, and/or institutions. Business Owner's Toolkit: General Ledger from Wolters Kluwer. General Ledger Entries from NetMBA Business Knowledge Center.


high-performance computingsupercomputinghigh performance computing
The Internet PrimeNet Server supports GIMPS's grid computing approach, one of the earliest and most successful grid computing projects, since 1997. Quasi-opportunistic supercomputing is a form of distributed computing whereby the "super virtual computer" of many networked geographically disperse computers performs computing tasks that demand huge processing power. Quasi-opportunistic supercomputing aims to provide a higher quality of service than opportunistic grid computing by achieving more control over the assignment of tasks to distributed resources and the use of intelligence about the availability and reliability of individual systems within the supercomputing network.

Wireless sensor network

sensor networkwireless sensor networkssensor networks
If a centralized architecture is used in a sensor network and the central node fails, then the entire network will collapse, however the reliability of the sensor network can be increased by using a distributed control architecture. Distributed control is used in WSNs for the following reasons: There is also no centralised body to allocate the resources and they have to be self organized. The data gathered from wireless sensor networks is usually saved in the form of numerical data in a central base station.