With my latest (merged) patches to WebVfx, one can load plain old HTML
and QML files. They do not need webvfx script to initialize rendering -
with some caveats about the meaning of document-loaded. However, without
this loader change, plain resources need to prefaced with "plain:". The
loader producer can now do that and instead "webvfx:" is needed to tell
webvfx to wait for script in the content to call
WebVfx.renderReady(true) (unless you use "webvfx:plain:...").
Also, WebVfx can also now load HTML over HTTP. This is especially handy
if your content is updating itself with data from a web service.
Otherwise, you will run into cross-site-scripting errors.