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Lightstreamer
Lightstreamer is a web-based asynchronous messaging project, implementing the WebSocket protocol, the Comet model, the push technology paradigm, and the real-time web practices. Origin The first version of Lightstreamer was created at the end of 2000, as one of the first attempts to implement real-time data push to HTML pages without employing Java applets. The application domain driving most of the interest in push technology at that time was market data distribution for the financial services industry. In the following years, Lightstreamer was used within other application domains too, including aerospace telemetry, where NASA chose Lightstreamer to push live telemetry data for the International Space Station. Architecture The Lightstreamer Server is a high-performance engine that manages all the connections with the clients through the Internet. It integrates with the backend systems via custom adapters. The Data Adapter receives the real-time data flow from the data feed and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Push Technology
Push technology or server push is a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull/get, where the request for the transmission of information is initiated by the receiver or client. Push services are often based on information preferences expressed in advance. It is called a publish/subscribe model. A client "subscribes" to various information "channels" provided by a server; whenever new content is available on one of those channels, the server pushes that information out to the client. Push is sometimes emulated with a polling technique, particularly under circumstances where a real push is not possible, such as sites with security policies that reject incoming HTTP/S requests. General use Synchronous conferencing and instant messaging are typical examples of push services. Chat messages and sometimes files are pushed to the user as soon as they are received by the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet (programming)
Comet is a web application model in which a long-held HTTPS request allows a web server to push data to a browser, without the browser explicitly requesting it. ''Comet'' is an umbrella term, encompassing multiple techniques for achieving this interaction. All these methods rely on features included by default in browsers, such as JavaScript, rather than on non-default plugins. The Comet approach differs from the original model of the web, in which a browser requests a complete web page at a time. The use of Comet techniques in web development predates the use of the word ''Comet'' as a neologism for the collective techniques. Comet is known by several other names, including ''Ajax Push'', ''Reverse Ajax'', ''Two-way-web'', ''HTTP Streaming'', and '' HTTP push, HTTP server push'' among others. The term ''Comet'' is not an acronym, but was coined by Alex Russell in his 2006 blog post ''Comet: Low Latency Data for the Browser''. In recent years, the standardisation and widespread s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript. Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for the appearance of the document. HTML elements are the building blocks of HTML pages. With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links, quotes, and other items. HTML elements are delineated by ''tags'', written using angle brackets. Tags such as and directly introduce content into the page. Other tags such as surround ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Publish–subscribe Pattern
In software architecture, publish–subscribe is a messaging pattern where senders of messages, called publishers, do not program the messages to be sent directly to specific receivers, called subscribers, but instead categorize published messages into classes without knowledge of which subscribers, if any, there may be. Similarly, subscribers express interest in one or more classes and only receive messages that are of interest, without knowledge of which publishers, if any, there are. Publish–subscribe is a sibling of the message queue paradigm, and is typically one part of a larger message-oriented middleware system. Most messaging systems support both the pub/sub and message queue models in their API; e.g., Java Message Service (JMS). This pattern provides greater network scalability and a more dynamic network topology, with a resulting decreased flexibility to modify the publisher and the structure of the published data. Message filtering In the publish-subscribe mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Financial Services
Financial services are the Service (economics), economic services provided by the finance industry, which encompasses a broad range of businesses that manage money, including credit unions, banks, credit-card companies, insurance companies, accountancy companies, consumer finance, consumer-finance companies, brokerage firm, stock brokerages, investment management, investment funds, individual asset managers, and some government-sponsored enterprises. History The term "financial services" became more prevalent in the United States partly as a result of the Gramm-Leach-Bliley Act, GrammLeachBliley Act of the late 1990s, which enabled different types of companies operating in the U.S. financial services industry at that time to merge. Companies usually have two distinct approaches to this new type of business. One approach would be a bank that simply buys an insurance company or an investment bank, keeps the original brands of the acquired firm, and adds the Takeover, acquisit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Market Data
''For market data as used in marketing, see marketing information system'' In finance, market data is price and other related data for a financial instrument reported by a trading venue such as a stock exchange. Market data allows traders and investors to know the latest price and see historical trends for instruments such as equities, fixed-income products, derivatives, and currencies. The market data for a particular instrument would include the identifier of the instrument and where it was traded such as the ticker symbol and exchange code plus the latest bid and ask price and the time of the last trade. It may also include other information such as volume traded, bid, and offer sizes and static data about the financial instrument that may have come from a variety of sources. There are a number of financial data vendors that specialize in collecting, cleaning, collating, and distributing market data and this has become the most common way that traders and investors get a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Applets
Java applets were small applications written in the Java programming language, or another programming language that compiles to Java bytecode, and delivered to users in the form of Java bytecode. The user launched the Java applet from a web page, and the applet was then executed within a Java virtual machine (JVM) in a process separate from the web browser itself. A Java applet could appear in a frame of the web page, a new application window, Sun's AppletViewer, or a stand-alone tool for testing applets. Java applets were introduced in the first version of the Java language, which was released in 1995. Beginning in 2013, major web browsers began to phase out support for the underlying technology applets used to run, with applets becoming completely unable to be run by 2015–2017. Java applets were deprecated by Java 9 in 2017. Java applets were usually written in Java, but other languages such as Jython, JRuby, Pascal, Scala, NetRexx, or Eiffel (via SmartEi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-platform
In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the interpreters or run-time packages are common or standard components of all supported platforms. For example, a cross-platform application may run on Microsoft Windows, Linux, and macOS. Cross-platform software may run on many platforms, or as few as two. Some frameworks for cross-platform development are Codename One, Kivy, Qt, Flutter, NativeScript, Xamarin, Phonegap, Ionic, and React Native. Platforms ''Platform'' can refer to the type of processor (CPU) or other hardware on which an operating system (OS) or application runs, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Web
The real-time web is a computer network, network web using technologies and practices that enable users to receive information as soon as it is published by its authors, rather than requiring that they or their software check a source periodically for updates. Difference from real-time computing The real-time web is different from real-time computing in that there is no knowing when, or if, a response will be received. The information types transmitted this way are often short messages, status updates, news alerts, or links to longer documents. The content is often "soft" in that it is based on the social web—people's opinions, attitudes, thoughts, and interests—as opposed to hard news or facts. History Examples of real-time web are Facebook's newsfeed, and Twitter, implemented in social networking, search, and news sites. Benefits are said to include increased user engagement ("flow") and decreased server loads. In December 2009 real-time search facilities were added to Goog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers. Java was originally developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WebSocket
WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as in 2011. The current API specification allowing web applications to use this protocol is known as ''WebSockets''. It is a living standard maintained by the WHATWG and a successor to ''The WebSocket API'' from the W3C. WebSocket is distinct from HTTP. Both protocols are located at layer 7 in the OSI model and depend on TCP at layer 4. Although they are different, states that WebSocket "is designed to work over HTTP ports 443 and 80 as well as to support HTTP proxies and intermediaries", thus making it compatible with HTTP. To achieve compatibility, the WebSocket handshake uses the HTTP Upgrade header to change from the HTTP protocol to the WebSocket protocol. The WebSocket protocol enables interaction between a web browser (or other client application) and a web server with lower overhead th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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