What is Javascript?

Javascript is a programming language that is used to make web pages interactive. It runs on your visitor’s computer and so does not require constant downloads from your web site.

A Brief History of JavaScript

Proposed in 1962, the Internet was created in 1969, known then as the ARPANET, by the Advanced Research Projects Agency (ARPA), linking their four main computers in their four research headquarters in SouthWest USA. It had been four years since 1965, when they had first managed to connect two computers over the telephone system. By 1972, many computers in universities across the USA had been connected, and the email, newsgroup and telnet protocols were being developed. Many further internet protocols were developed in the 1970s and 1980s, such as FTP and Gopher, and the underlying TCP/IP protocol replaced the original NCP protocol in the early 1980s. And so the ARPANET became the Internet, a network of university and military computers connected to each other via many other computers, communicating using the TCP/IP protocol. The idea was that, even if the Cold War became real, and portions of the Internet were damaged by nuclear war, the remaining links could take over so the internet could still function.
The World Wide Web (which basically means using the HTTP protocol to retrieve hyperlinked documents) was proposed in March 1989 by Tim Berners-Lee, a British computer specialist, at the European Laboratory for Particle Physics (CERN) for Swiss scientists, so that they could easily publish and share their research with the 12 nations of the high-energy physics community. He created the world’s first browser, named ‘WorldWideWeb’, in 1990, and released it in 1991. In 1992, browsers became a worldwide tool for transmission of text based information, using the HTTP protocol. In 1993 the NCSA mosaic browser was created and offered the oportunity to use inline images, and colours and hyperlinks as well as plain text. It was also the first browser to run in a graphical interface environment. The first version of Netscape was released in 1994, written by a break-away group from the original Mosaic team.

The Javascript language is one of the most useful to come along in the history of the world wide web. It allows websites to be built that are much more interactive than the ones that came before them. Javascript was actually created to make better web browsers but it soon became obvious that it was also useful forwebsite developers. The result is the world wide web that we know today, with all of its interactivity.

Javascript was created during the mid nineties as a way to make web browsers more interactive. Up until that time most websites were very dull as they usually contained little besides text and had almost no interactivity. In order to address this problem when Netscape were developing their updated version of the Navigator browser they created Javascript in order to allow them to build a browser that would be more functional. With this they were very successful and Javascript soon became widely used for a number of other applications as well.

The main use of Javascript quickly went from building a better web browser to building a better website. It is used mainly to build dynamic web pages. A dynamic web page is simply one that shows new content every time somebody visits. In the early days of the web this wasn’t possible because of the limitations of HTML. It was really the development of PHP that made dynamic sites possible. However even this proved to be of limited value. What was really needed was a coding language that would allow for the development of sites that weren’t just dynamic but actually interactive.

This is something that Javascript made possible. On our own web siteYozo.be, we use Javascript intensely to make the page talk to the visitors as naturally as possible. It takes some skill, but it’s actually surprisingly simple.

Unlike most other programing languages that are used to create web pages it soon became apparent that there were a number of other potential uses for Javascript. Not only is it used to create web pages it is widely used in the development of PDF documents. This allows documents to be interactive as well. Javascript is also widely used in the development of desk top applications. The main reason for the popularity of Javascript is that it is a fairly easy language to learn and to code with.

One of the areas that has caused some controversy with Javascript is the name. It of course has a similar name to the popular programming language Java. In fact there is no relationship between them at all. They were developed completely independently of each other. However Sun Microsystems who did develop Java were involved in the announcement of the name, adding to the confusion. Most people have viewed this as a marketing ploy, a way to attract attention Netscape’s new browser. Although exactly what was in it for Sun Microsystems was never quite clear. Clearly some sort of arrangement was made but just what that is we are unlikely to ever know.

JavaScript name terminology

These names are subject to interpretation by the browser developers. For example, browsers may support what they call JavaScript1.5, but not even support DHTML. This makes the JavaScript version unreliable, do not rely on it.

ECMAscript : The core syntax for JavaScript, defining control stuctures, intrinsic objects and variable types, operators, functions, scope, etc.

DOM level 0 : Says how to refer to forms, inputs, images, links and anchors as children of the document object.

Layers DOM : Says how to refer to positioned elements (layers) and modify their style as children of the document object with nested references.

Proprietary DOM : Says how to refer to elements and modify their style using the all collection of the document or parent object and the style child object of the element.

W3C DOM : Says how to refer to elements and modify their style using various getElementBy… methods of the document or parent object and the style child object of the element. Also says how to represent all document elements as a tree structure. Also allows elements to be created, modified or deleted even after the document has loaded.

Mocha : An early name for JavaScript, not recognised by most browsers.

LiveWire : An early name for JavaScript, not recognised by most browsers, used as the name of Netscape’s server side JavaScript.

LiveScript : An early name for JavaScript, recognised by most browsers.

JavaScript : A collective name for all versions of JavaScript.

JavaScript1.0 : The first version of JavaScript to be released – Early ECMAscript + DOM level 0 without images.

JavaScript1.1 : Early ECMAscript + DOM level 0.

JavaScript1.2 : ECMAscript + DOM level 0 + layers or proprietary DOM.

JavaScript1.3 : More advanced ECMAscript + DOM level 0 + layers or proprietary DOM.

JavaScript1.4 : Server side JavaScript.

JavaScript1.5 : Even more advanced ECMAscript + DOM level 0 + W3C DOM.

JavaScript2.0 : JavaScript 1.5 with several extensions added by Mozilla – may become a future standard.

JScript : Microsoft’s JavaScript variations with extended core features.

Active scripting : Microsoft’s user friendly way of saying ‘JScript’.

JellyScript : WebTV’s interpretation of JavaScript.

InScript : iCab 3-‘s interpretation of JavaScript.

ECMAscript Mobile Profile : Parts of ECMAScript, basic JavaScript APIs, and DOM, all mixed together in a single specification. Incompatible in far too many ways with existing pages on the Web, current browsers, the ECMAScript pecification, the DOM specifications, the JavaScript documentation, and other well established practices. ECMAScript Mobile Profile should be ignored. It is harmful to the Web because of its incompatibilities.

 

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