sid datta wrote:
BTW, does SVG have an "extension" system where an application can put its own data, that is outside the standard and other applications might not understand ? That can be another way of putting our own stuff in before SVG approves it.
SVG does have an "extension" system. SVG is an application of XML. The X stands for extensible. And Inkscape extends SVG all over the place. You can see the difference when saving Inkscape SVG or Plain SVG. Or rather, you shouldn't see the difference unless you look at the XML markup inside the file. We've made a pact that our extensions to SVG shouldn't change how the file is rendered in other viewers. Our SVG extensions store many sorts of metadata to help Inkscape edit the files but not different objects to render. (With the regrettable exception of FlowText.)
Aaron Spike