SVG embedded inside of XML is only currently support in builds of Mozilla with the ./configure flags set to enable SVG.
www.croczilla.com is the primary source of the GDI+ builds (which are better than libart ones). But the latest one there is off of the 1.1 branch.
I may compile a 1.2 build with GDI+ with Visual Studio if I ever get around to it...
For Linux and non-Windows OS's, you are stuck with the libart builds which suffice, but have a nasty coloring bug last I checked.
The ability to embed SVG directly in other markup is staggering - I have a XUL sidebar with SVG and MathML namespaces directly inside to create a function grapher... it is pretty cool.
Mozilla builds are typically compiled without SVG support, and IE still has the majority, you will need to resort to the <object> and the excellent Adobe SVG Viewer plugin. It supports some of the SVG DOM, and implements some DOM2 Interfaces which IE doesn't in order to have solid scripting ability. Its support of SVG is the best you can use in any browser, as Mozilla's native implementation is still far from complete.
If you have any SVG questions, between Alex Vincent, I, and any unknown SVG enthusiasts on these boards should be able to help. Also, these posts are most appropriate in the XML forum, so I'll move this thread there.
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