Both have positives and negatives. SVG is more widely used on-line, but not as much as say Flash. CGM viewers are not as common, but PTC offers a viewer (though expensive). My main suggestion is to determine your audience. If you can control what is being used to view the pages (say only business customers), go with CGM and get the PTC plug-in. If you don't have much say (everone else), go with SVG. The best option, however, may be to look into Flash. Though this doesn't get you all the way to where you want, it's close. http://sourceforge.net/projects/svg2swf/