Editing Document Object Model (section)

==History==
The history of the Document Object Model is intertwined with the history of the "[[browser wars]]" of the late 1990s between [[Netscape Navigator]] and [[Microsoft Internet Explorer]], as well as with that of [[JavaScript]] and [[JScript]], the first [[scripting language]]s to be widely [[Implementation|implemented]] in the [[JavaScript engine]]s of [[web browser]]s.

JavaScript was released by [[Netscape Communications]] in 1995 within Netscape Navigator 2.0. Netscape's competitor, [[Microsoft]], released [[Internet Explorer 3|Internet Explorer 3.0]] the following year with a reimplementation of JavaScript called JScript. JavaScript and JScript let [[web developer]]s create web pages with [[client-side]] interactivity. The limited facilities for detecting user-generated [[Event (computing)|events]] and modifying the HTML document in the first generation of these languages eventually became known as "DOM Level 0" or "Legacy DOM." No independent standard was developed for DOM Level 0, but it was partly described in the specifications for [[HTML4|HTML 4]].

Legacy DOM was limited in the kinds of [[HTML element|element]]s that could be accessed. [[Form (web)|Form]], [[Hyperlink|link]] and image elements could be referenced with a hierarchical name that began with the root document object. A hierarchical name could make use of either the names or the [[Sequence|sequential index]] of the traversed elements. For example, a [[Text box|form input element]] could be accessed as either <code>document.myForm.myInput</code> or <code>document.forms[0].elements[0]</code>.

The Legacy DOM enabled client-side form validation and simple interface interactivity like creating [[tooltip]]s.

In 1997, Netscape and Microsoft released version 4.0 of Netscape Navigator and Internet Explorer respectively, adding support for [[Dynamic HTML]] (DHTML) functionality enabling changes to a loaded HTML document. DHTML required extensions to the rudimentary document object that was available in the Legacy DOM implementations. Although the Legacy DOM implementations were largely compatible since JScript was based on JavaScript, the DHTML DOM extensions were developed in parallel by each browser maker and remained incompatible. These versions of the DOM became known as the "Intermediate DOM".

After the standardization of [[ECMAScript]], the [[World Wide Web Consortium|W3C]] DOM Working Group began drafting a standard DOM specification. The completed specification, known as "DOM Level 1", became a W3C Recommendation in late 1998. By 2005, large parts of W3C DOM were well-supported by common ECMAScript-enabled browsers, including [[Internet Explorer 6]] (from 2001), [[Opera (web browser)|Opera]], [[Safari (web browser)|Safari]] and [[Gecko (layout engine)|Gecko]]-based browsers (like [[Mozilla Application Suite|Mozilla]], [[Mozilla Firefox|Firefox]], [[SeaMonkey]] and [[Camino (web browser)|Camino]]).