Microsoft created an implementation of JavaScript called JScript, which was introduced in Internet Explorer version 4. Microsoft allowed scripts to be written in Visual Basic ("VBScript") as well. Microsoft extended Netscape's implementation to include the ability to access and modify just about any HTML element and style sheet property. It also included a variety of event handlers and provisions for hooking into ActiveX controls and Java applets. Instead of supporting the TrueDoc font conventions, Microsoft downloadable fonts are TrueType.
For these reasons, the HTML author will usually be forced to test the viewer's browser make and use this information in the script language - testing for various implementation specific things.
To address these issues, the World Wide Web Consortium has recommended a platform independent 'document object model' (DOM) which describes the various parts of an HTML document and access methods to modify them. It is a work-in-progress; go to http://www.w3.org/DOM/ for the latest information.
What is the Document Object Model?
The Document Object Model is a platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page. This is an overview of DOM-related materials here at W3C and around the web.
Why the Document Object Model?
"Dynamic HTML" is a term used by some vendors to describe the combination of HTML, style sheets and scripts that allows documents to be animated. The W3C has received several submissions from members companies on the way in which the object model of HTML documents should be exposed to scripts. These submissions do not propose any new HTML tags or style sheet technology. The W3C DOM WG is working hard to make sure interoperable and scripting-language neutral solutions are agreed upon. W3C Activity Statement on the Document Object Model The W3C DOM Activity statement is the W3C statement of direction concerning the evolution of the Document Object Model. Look here for information about the goals of the work and the current situation.