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SpiderMonkey
SpiderMonkey is the first JavaScript engine, written by Brendan Eich at Netscape Communications, later released as open source and currently maintained by the Mozilla Foundation. It is used in the Firefox web browser. History Eich "wrote JavaScript in ten days" in 1995, having been "recruited to Netscape with the promise of 'doing Scheme' in the browser". (The idea of using Scheme was abandoned when "engineering management ecidedthat the language must 'look like Java.) In late 1996, Eich, needing to "pay off hesubstantial technical debt" left from the first year, "stayed home for two weeks to rewrite Mocha as the codebase that became known as SpiderMonkey". (Mocha was the original working name for the language.) In 2011, Eich transferred management of the SpiderMonkey code to Dave Mandelin. Versions Standards SpiderMonkey implements the ECMA-262 specification (ECMAScript). ECMA-357 (ECMAScript for XML (E4X)) was dropped in early 2013. Internals SpiderMonkey is writ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ECMAScript For XML
ECMAScript for XML (E4X) is the standarprogramming language extension that adds native XML support to ECMAScript (which includes ActionScript, JavaScript, and JScript). The goal is to provide an alternative to DOM interfaces that uses a simpler syntax for accessing XML documents. It also offers a new way of making XML visible. Before the release of E4X, XML was always accessed at an object level. E4X instead treats XML as a primitive (like characters, integers, and booleans). This implies faster access, better support, and acceptance as a building block (data structure) of a program. E4X is standardized by Ecma International in thECMA-357 standard The first edition was published in June 2004, the second edition in December 2005. The E4X standard was deprecated by the Mozilla Foundation in 2014. Browser support E4X is supported by Mozilla's Rhino, used in OpenOffice.org and several other projects. It is also supported by Tamarin, the JavaScript engine used in the Flash virtual ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brendan Eich
Brendan Eich (; born July 4, 1961) is an American computer programmer and technology executive. He created the JavaScript programming language and co-founded the Mozilla project, the Mozilla Foundation, and the Mozilla Corporation. He served as the Mozilla Corporation's chief technical officer before he was appointed chief executive officer, but resigned shortly after his appointment due to controversy over his opposition to same-sex marriage. He subsequently became the CEO of Brave Software. Early life Eich grew up in Pittsburgh; Gaithersburg, Maryland; and Palo Alto, and he attended Ellwood P. Cubberley High School, graduating in the class of 1979. He received his bachelor's degree in mathematics and computer science at Santa Clara University, and he received his master's degree in 1985 from the University of Illinois at Urbana–Champaign. Eich is Roman Catholic. He began his career at Silicon Graphics, working for seven years on operating system and network code.. He th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript Engine
A JavaScript engine is a software component that executes JavaScript code. The first JavaScript engines were mere interpreters, but all relevant modern engines use just-in-time compilation for improved performance. JavaScript engines are typically developed by web browser vendors, and every major browser has one. In a browser, the JavaScript engine runs in concert with the rendering engine via the Document Object Model. The use of JavaScript engines is not limited to browsers. For example, the V8 engine is a core component of the Node.js and Deno runtime systems. Since ECMAScript is the standardized specification of JavaScript, ECMAScript engine is another name for these engines. With the advent of WebAssembly, some engines can also execute this code in the same sandbox as regular JavaScript code. History The first JavaScript engine was created by Brendan Eich in 1995 for the Netscape Navigator web browser. It was a rudimentary interpreter for the nascent language Eich inven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ECMAScript
ECMAScript (; ES) is a JavaScript standard intended to ensure the interoperability of web pages across different browsers. It is standardized by Ecma International in the documenECMA-262 ECMAScript is commonly used for client-side scripting on the World Wide Web, and it is increasingly being used for writing server-side applications and services using and other runtime environments. ECMAScript, ECMA-262 and JavaScript ECMA-262, or the ''ECMAScript Language Specification'', defines the ''ECMAScript Language'', or just ECMAScript. ECMA-262 specifies only language syntax and the semantics of the core API, such as , , and , while valid implementations of JavaScript add their own functionality such as input-output and file-system handling. History The ECMAScript specification is a standardized specification of a scripting language developed by Brendan Eich of Netscape; initially named Mocha, then LiveScript, and finally JavaScript. In December 1995, Sun Microsystems and Netsc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Just-in-time Compilation
In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compilation during execution of a program (at run time) rather than before execution. This may consist of source code translation but is more commonly bytecode translation to machine code, which is then executed directly. A system implementing a JIT compiler typically continuously analyses the code being executed and identifies parts of the code where the speedup gained from compilation or recompilation would outweigh the overhead of compiling that code. JIT compilation is a combination of the two traditional approaches to translation to machine code—ahead-of-time compilation (AOT), and interpretation—and combines some advantages and drawbacks of both. Roughly, JIT compilation combines the speed of compiled code with the flexibility of interpretation, with the overhead of an interpreter and the additional overhead of compil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefox
Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and anticipated web standards. In November 2017, Firefox began incorporating new technology under the code name "Quantum" to promote parallelism and a more intuitive user interface. Firefox is available for Windows 7 and later versions, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems, including FreeBSD, OpenBSD, NetBSD, illumos, and Solaris Unix. It is also available for Android and iOS. However, as with all other iOS web browsers, the iOS version uses the WebKit layout engine instead of Gecko due to platform requirements. An optimized version is also available on the Amazon Fire TV as one of the two main browsers available with Amazon's Silk Browser. Firefox was created in 2002 under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracing JIT
Tracing just-in-time compilation is a technique used by virtual machines to optimize the execution of a program at runtime. This is done by recording a linear sequence of frequently executed operations, compiling them to native machine code and executing them. This is opposed to traditional just-in-time (JIT) compilers that work on a per-method basis. Overview Just-in-time compilation is a technique to increase execution speed of programs by compiling parts of a program to machine code at runtime. One way to categorize different JIT compilers is by their compilation scope. Whereas method-based JIT compilers translate one method at a time to machine code, tracing JITs use frequently executed loops as their unit of compilation. Tracing JITs are based on the assumptions that programs spend most of their time in some loops of the program ("hot loops") and subsequent loop iterations often take similar paths. Virtual machines that have a tracing JIT are often mixed-mode execution en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Flow
In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an ''imperative programming'' language from a '' declarative programming'' language. Within an imperative programming language, a ''control flow statement'' is a statement that results in a choice being made as to which of two or more paths to follow. For non-strict functional languages, functions and language constructs exist to achieve the same result, but they are usually not termed control flow statements. A set of statements is in turn generally structured as a block, which in addition to grouping, also defines a lexical scope. Interrupts and signals are low-level mechanisms that can alter the flow of control in a way similar to a subroutine, but usually occur as a response to some external stimulus or event (that can occur asynchronously), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Debt
In software development, technical debt (also known as design debt or code debt) is the implied cost of additional rework caused by choosing an easy (limited) solution now instead of using a better approach that would take longer. Analogous with monetary debt, if technical debt is not repaid, it can accumulate "interest", making it harder to implement changes. Unaddressed technical debt increases software entropy and cost of further rework. Similarly to monetary debt, technical debt is not necessarily a bad thing, and sometimes (e.g. as a proof-of-concept) is required to move projects forward. On the other hand, some experts claim that the "technical debt" metaphor tends to minimize the ramifications, which results in insufficient prioritization of the necessary work to correct it. As a change is started on a codebase, there is often the need to make other coordinated changes in other parts of the codebase or documentation. Changes required that are not completed are considered de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefox 3
Mozilla Firefox 3.0 is a version of the Firefox web browser released on June 17, 2008, by the Mozilla Corporation. Firefox 3.0 uses version 1.9 of the Gecko layout engine for displaying web pages. This version fixes many bugs, improves standards compliance, and implements many new web APIs compared to Firefox 2.0. Other new features include a redesigned download manager, a new "Places" system for storing bookmarks and history, and separate themes for different operating systems. Firefox 3.0 had over 8 million unique downloads the day it was released, and by July 2008 held over 5.6% of the recorded usage share of web browsers. Estimates of Firefox 3.0's global market share were generally in the range of 4–5%, and then dropped as users migrated to Firefox 3.5 and later Firefox 3.6. Partially as a result of this, between mid-December 2009 and the end of January 2010, Firefox 3.5 was the most popular browser (when counting individual browser versions), passing Internet Explore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called '' garbage''. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect performance as a result. Resources other than memory, such as network sockets, database handles, windows, file descriptors, and device descriptors, are not typically handled by garbage collection, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Type
In computer science and computer programming, a data type (or simply type) is a set of possible values and a set of allowed operations on it. A data type tells the compiler or interpreter how the programmer intends to use the data. Most programming languages support basic data types of integer numbers (of varying sizes), floating-point numbers (which approximate real numbers), characters and Booleans. A data type constrains the possible values that an expression, such as a variable or a function, might take. This data type defines the operations that can be done on the data, the meaning of the data, and the way values of that type can be stored. Concept A data type is a collection or grouping of data values. Such a grouping may be defined for many reasons: similarity, convenience, or to focus the attention. It is frequently a matter of good organization that aids the understanding of complex definitions. Almost all programming languages explicitly include the notion of data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
