">http://entropymine.com/jason/testbed/pngtrans/</a>

<p>
Not all possible results are shown; there are too many combinations
of background colors and shapes of the opaque region. However, I
intend to include every result that actually occurs in a mainstream
browser. If I am missing any, please 
<a href="mailto:jason1@pobox.com">let me know</a>.

</p><p>It's come to my attention that my images which show how
alpha transparency should look are not quite perfect
in regard to precisely how transparent they are