As with any technology, developing SVG content can too easily go wrong on little things in multiple places. I believe it's a small number of exactly those little things that many people creating their (first) pieces of SVG keep encountering. Though there are lots of helpful bits in tools and documentation around they are too scattered for especially the novice SVG developer. Therefore i think it would be incredibly useful if, just as the widely popular Web Developer extension for HTML, CSS, etc., a SVG Developers Firefox extension would come into existance. There's already the nice SVG Switcher extension that allows you to choose between 2 renderers. But what about the following functionality? Check MIME. Validate SVG. Check browsers compatibility. Advice workarounds for bugs. WebStart Batik. save raster. detect common coding errors. specialized search. links to spec(s), svg.org, wiki and svg.startpagina.nl. Maybe cooperate with Chris Pederick of the award-winning Web Developer extension? If you're the one to start this off, ask for the shiny donkey on #svg for some help