How can I create SVG graphics using JavaScript?
Do all browsers support SVG?
Have a look at this list on Wikipedia about which browsers support SVG. It also provides links to more details in the footnotes. Firefox for example supports basic SVG, but at the moment lacks most animation features.
A tutorial about how to create SVG objects using Javascript can be found here:
var svgns = "http://www.w3.org/2000/svg";
var svgDocument = evt.target.ownerDocument;
var shape = svgDocument.createElementNS(svgns, "circle");
shape.setAttributeNS(null, "cx", 25);
shape.setAttributeNS(null, "cy", 25);
shape.setAttributeNS(null, "r", 20);
shape.setAttributeNS(null, "fill", "green");