Summary: Cyrix (and subsequently, VIA) have an implied license to Intel's patents; allowing them to develop x86 hardware.
How that differs from AMD: AMD and Intel have a full cross-license on technologies. This means, AMD can utilize Intel resources to integrate AVX-512, a ring-bus, etc (and vice versa).
VIA can not. They must develop those technologies independently, in a compatible manner.
Summary: Cyrix (and subsequently, VIA) have an implied license to Intel's patents; allowing them to develop x86 hardware.
How that differs from AMD: AMD and Intel have a full cross-license on technologies. This means, AMD can utilize Intel resources to integrate AVX-512, a ring-bus, etc (and vice versa). VIA can not. They must develop those technologies independently, in a compatible manner.