I haven't used SVG for ages, although there's a demo-type thing I want to build with it sometime (a "coordination navigator" with GWS->DOM->XSLT->SVG, hopefully about twenty lines of "actual code"). Anyhow: last I looked, SVG was incredibly super-powerful, hence you'd only expect a small handful of conformant-or-very-close implementations (eg. Adobe, Batik).

Nooooo. Things have changed somewhat. Implementations abound. There's SVG support not only in Illustrator, but Maya and even Visio. A major-looking Corel toolset ("dramatically speeds up the development and maintenance of data-driven, enterprise-class graphical applications for Extranets and Intranets").

And, most surprisingly, a standard (W3C Rec) mobile subset (actually two, "mobile" and "tiny") suitable for small devices: J2ME mobile phones, say. Wow.

Historical addendum: SVG was used for the first-ever third-party Groove tool (RAG, injectable version at Cabezal, minor revisions since the original Agora version of Oct.2000 - screenshot here).