Re: XML + XSLT = SVG using FOP example needed...

SVG is merely one of several output formats that FOP supports. The idea is basically that you fire up your SVG viewer and see a rendering of the page, using, in effect, XSL-FO as an SVG "driver" format. (It did seem like a somewhat bizarre thing to do, but hey, SVG is cool so why not?)

There are use cases, you know the dreaded problem to
put a box around a string (proportional font of course).

But Tom, when I tried this oh many months ago, it didn't work very well: the SVG came out but the rendering was poor. (I just did it configuring FOP from the command line.) So I'm afraid that's not much help since hopefully the implementation has improved since then,

It seems to have been degraded, the renderer seems not
be actively maintained currently :-(

FOP "renders SVG" in the sense that you can pass SVG as part of your FO, and FOP will render it; but it will also render its FO content *in* SVG, and that's what I think you (Tom) are asking about.