downward compatible; backward compatible; upward compatible; forward compatible; providing the same function while being more effective (esp. in games)
upward compatible; forward compatible; downward compatible; backward compatible; providing the same function while being less effective (esp. in games)
compatible machine; clone (e.g. IBM PC); workalike
backward compatible; downward compatible
binary level compatibility
binary level compatibility
compatibility test; interoperability test
forward compatible; upward compatible