Copyleft is GPL. It is obscure only because most now simply list licence as GPL.
------------------------------------------------------------------------------------------------------------- the way ive been told you have three different cases GNU type aka copy left: make your copies and send me any changes (next in line gets same rights) M$ type aka copyright : no copies that i didn't make and don't mess with my code BSD type aka copy center: make as many copies as you want (the center refers to shops like kinko's)
