"XWD, an acronym for Cross-Wheel Drive, is an advanced all-wheel drive system designed by Haldex in partnership with Saab[1]. Also known as Haldex Generation 4, it is an intelligent permanent all-wheel drive system that can pre-emptively and continuously change torque distribution before wheel slip occurs."
"While the Haldex Generation 4 system will be made available to other automobile manufacturers starting 2009, the XWD moniker is a trademark owned by Saab Automobile AB, and thus cannot be used by any other make."