Assembly languages aren't even defined for the platform, they're defined for the compilers (more technically, the assemblers). There aren't even standard assemb

Assembly languages aren't even defined for the platform, they're defined for the compilers (more technically, the assemblers). There aren't even standard assemblers, almost every compiler will roll their own (including VMs and JITs). Intel vs AT&T syntax just standardize a few conventions, AT&T requiring more explicitness (and of course, flipping the position of source/destination operands).