The DVD+RW camp, which includes Hewlett-Packard, Dell and Philips, plans to put so-called “double-layer” DVD recording devices on the market by next spring. Discs on these systems are expected to hold 8.5GB, or four hours of DVD-quality video. That’s about the same amount as the DVDs studios use to issue movies.

But the so-called “dash” camp promoting the DVD-R and DVD-RW formats also is working on dual-layer recording, which involves writing data on two separate surfaces. And unlike in the videotape-standard battle between VHS and Betamax, “plus” and “dash” may be able to coexist for some time to come.

“I do believe that the plus guys are going to get there first,” said Robert DeMoulin, marketing manager for branded optical products at Sony. Sony, like some other manufacturers, makes DVD recorders that combine both plus and dash technology.

Retail movies sold on DVDs typically come with data written on two layers. But the commercial process involves “stamping” the discs rather than burning spots with a laser.

News source: C|Net Personal Technology News