[wyoung2]

If you leave off the "pikchr" tag or use something else like "PikchrSource", then the renderer doesn't trigger.

If you want to see it both ways, Fossil renders the diagrams with an Alt or Ctrl-click handler attached (depending on platform) that toggles between the SVG and the fixed-width source code view.

And if you don't like the modifier key, you can tag a diagram "pikchr toggle" to make it toggle with a simple left-click.

[OJFord]

Sure, but usually specifying "pikchr" (or whatever) means syntax-highlight as appropriate to that language; not execute as that language.