If the Mandelbrot image window is blank, in a new tab
visit about:config, then search for "fileuri", and change
the security.fileuri.strict_origin_policy to false.
Mandelbrot examples can be coded as "XML documents."
You can copy-and-paste the XML code
for an example into this text input box. Click "Apply" to
import the example. Click "Cancel" or
press ESC to cancel. The "Grab Current Example" button
reloads the XML for the example that
is currently shown in the main window (use this to
cancel any edit you may have made without
the need to reopen this editor).