DegustatoR
Legend
It's not a trademark. You've quoted what it is yourself - "a hardware–software solution".You cannot change the definition of proprietary to suit you case. Its a trademark. AMD cannot claim propriety of open standards. Wiki sates it uses open standards. But that excuse is indeed better than calling wikipedia "wrong".
This can be said about Gsync too then as it uses HDMI standards as we speak.The HDMI freesync version does not invalidate any of this discussion, as long as there exists freesync using vesa standards you cannot claim it proprietary. Its a trademark that covers both free and proprietary in older hdmi products.