Kevin Hughes wrote a beautiful Color Picker application in about 100k of SVG. The code is Creative Commons-licensed.
More telling are Kev’s notes on SVG, in which he tells the good, the bad, and the ugly. His recommendations:
Looking ahead, there could stand to be efforts for making today’s dynamic languages ready for real GUI application development using SVG. This mostly means adding support for multithreading, Unicode, and internationalization. Once these things are well baked into PHP or other dynamic language, there is no stopping the new application development paradigm. With PHP support you’d convert hordes of developers immediately. Applications could run on the Web and be deployed on the desktop with the same code, and could be created and edited by just about anybody, if you wanted them to. Every application could print in full PDF quality. Sounds a bit like the promise of HyperCard, but with vector graphics…
With SVG we are now at the edge of a new shift in how people think about applications, just as we were when the Web first started. We’ve had a long enough fight trying to get our content out of proprietary data jail formats, and sure, we have a ways to go – but every HTML page I wrote in 1993 still renders the same in modern browsers on modern computers on every major platform; with how many programs can you say that? Let’s try to do the same for applications and help make them more future-proof with SVG.