New software lets owners of veteran Macs install Tiger on their old computer.

Available now from Other World Computing (OWC) the software, XPostFacto 4.0, is an application that lets Mac users run Mac OS X 10.4 Tiger on older Macs that Apple no longer supports.

OWC president Larry O'Connor said: "Macs last an amazingly long time and XPostFacto helps them go that much longer, even allowing models built ten years ago to continue to take advantage of Apple's latest and greatest OS.

The software supports Mac OS X 10.4 and will also install Mac OS X 10.2-10.4. It works with machines that Apple originally supported in Mac OS X but no longer supports in 10.4 (the original iMac, original iBook, Beige G3, Wallstreet and Lombard PowerBooks).

It also works with Macs Apple never supported for OS X, including the 7300-9600 series (though a G3 or G4 processor upgrade is required for Mac OS X 10.3 and later).

The software is free though the company states: "Users are encouraged to pay a $25 registration fee to support the continued development of XPostFacto".