gnome-control-center/capplets/screensaver/screensavers/halo.xml

<?xml version="1.0" encoding="ISO-8859-1"?>

<screensaver name="halo" _label="Halo">

    <command arg="-root"/>

    <number _label="Number of Colors." _low-label="Colors:" id="colors"
            type="spinbutton" default="100" arg="-colors %" low="1"
            high="256"/>

    <number _label="Number of circles to use." _low-label="Count:"
            id="count" type="spinbutton" default="10" arg="-count %"
            low="1" high="100"/>

    <number _label="Speed of Motion." _low-label="Faster" id="delay"
            type="slider" default="2" arg="-delay %" low="1"
            _high-label="Slower" high="500000"/>

    <boolean _label="Display screensaver in monochrome." arg-unset=""
             id="monochrome" test="mono" arg-set="-mono"/>

    <boolean _label="Use a gradient of colors between circles."
             arg-unset="-mode seuss" id="mode" arg-set="-mode ramp"/>

    <boolean _label="Animate circles." arg-unset="" id="animate"
             arg-set="-animate"/>

    <boolean _label="Cycle through colormap." arg-unset="-no-cycle"
             id="cycle" arg-set="-cycle"/>

    <_description>This draws trippy psychedelic circular patterns that hurt to look at.  It can also animate the control-points, but that takes a lot of CPU and bandwidth.  Written by Jamie Zawinski.</_description>
</screensaver>