Options for the new machines will include Apple's new wireless-networking technology, Airport Extreme, which supports speeds of 54 megabits per second and is also backward-compatible with standard Wi-Fi gear.

FORBES: Magazine Article

While both Opteron and Itanium ran newer 64-bit software, AMD's chip was also backward-compatible, enabling it to run software written for older 32-bit processors.

FORBES

And all of a sudden your relatively old refrigerator or air conditioner doesn't work because the new operating system isn't backward-compatible with the systems in these devices.

CNN: Home, sweet networked home

The Aircell Smartphone will be backward-compatible with all Aircell Axxess communications systems currently in production, and available as a drop-in replacement for the company's prolific Aircell Axxess flush-mount handset.

ENGADGET: Aircell announces world's first 'airborne smartphone'

But it's backward-compatible with the B standard, meaning that a router or other access point that uses the G standard can also support a notebook outfitted for the B standard, but only at the slower speed.

FORBES: Magazine Article

When it is finished in the second half of this year, the specification is expected to deliver data rates of 10Mbps for home phoneline networking and also to be backward-compatible and interoperate with existing HomePNA 1Mbps technology.

CNN: Home networking group picks next phoneline spec

Backward compatible with USB 2.0, G-Technology's USB 3.0 drives deliver speeds 10 times faster than USB 2.0 and six times faster than FireWire 800.

ENGADGET: G-Technology kicks out USB 3.0 G-Drives for Macs, keeps your Retina MacBook Pro well-fed