[sldev] ESC exempt from open source and GPL licensing?

[Gordon Wendt]

It is my understanding that per the GPL which the viewer is licensed
under all derivative works (viewers) have to have a copy of the
license and the source code either included with them or easily
accessible however the OnRez viewer by the Electric Sheep Company does
not have either which is a violation of the license, I may be mistaken
but I have also gotten the understanding that ESC is somehow exempted
from this license, now for the part that effects open sourcing, how?
why? and why is our open source work being used for commercial gain by
them without them giving back to us and yes I realize they claim to
submit stuff back but that's still not a fair tradeback if they aren't
following the licensing agreement for using the open source code.