30.5.1.1. Synchronized Multimedia Integration Language (SMIL)

30.5.1.2. Scalable Vector Graphics (SVG)

SVG is a language for describing two-dimensional graphics in XML. SVG allows for three types of graphic objects: vector graphic shapes (e.g., paths consisting of straight lines and curves), images and text. Graphical objects can be grouped, styled, transformed and composited into previously rendered objects. Text can be in any XML namespace suitable to the application, which enhances searchability and accessibility of the SVG graphics. The feature set includes nested transformations, clipping paths, alpha masks, filter effects, template objects and extensibility.

The following sample SVG code (taken from the W3C Recommendation) creates an SVG document fragment that contains a red circle with a blue outline (stroke):

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20001102//EN" 
"http://www.w3.org/TR/2000/CR-SVG-20001102/DTD/svg-20001102.dtd">
<svg width="12cm" height="4cm">
<desc>Example circle01 - circle expressed in physical units</desc>

<circle cx="6cm" cy="2cm" r="1cm"
        style="fill:red; stroke:blue; stroke-width:0.1cm" />
</svg>

The SVG standard provides ways to describe paths, fills, a variety of shapes, special filters, text, and basic animation.

Adobe offers tools for both creating and viewing SVG files. The drawing program Illustrator 9 can now export .svg files directly. Adobe's SVG Viewer is a browser plug-in available for Navigator and Internet Explorer 4 and higher for Windows and Macintosh that allows SVG files to display in the browser window.

30.5.1.3. Mathematical Markup Language (MathML)

Because there is no way to reproduce mathematical equations directly using HTML, authors have resorted to inserting graphical images of equations into the flow of text. This effectively removes the information from the structure of the document. MathML allows the information to remain in the document in a meaningful way. With adequate style sheets, mathematical notation can be formatted for high-quality visual presentation. Several vendors offer applets and plug-ins that allow the display of MathML information in browser windows.

30.5.1.4. Resource Description Framework (RDF)

RDF is an XML application used to define the structure of metadata for documents (i.e., data that is useful for indexing, navigating, and searching a site). A formal method for describing the contents of a web site, page, or resource could be useful to automated agents that search the Web for specific information. Metadata could be used in the following ways:

• For resource discovery to provide better search engine capabilities

• In cataloging for describing the content and content relationships available at a particular web site, page, or digital library

• By intelligent software agents to facilitate knowledge sharing and exchange

• In content rating

• In describing collections of pages that represent a single logical "document"

• For digital signatures that allow electronic commerce, collaboration, and other "trust"-based applications