Microsoft's Windows Vice President Jim Allchin has dismissed Mac OS X 10.4 as "a peripheral to the iPod" while admitting that the constant delay in shipping Longhorn (the code-name for the next Microsoft OS) is "a problem," Newsweek reports in a look at the intensification of competition between Apple and Microsoft regarding operating systems.

Allchin also suggested features such as Tiger's Dashboard feature were inspired by Longhorn - a charge Apple CEO Steve Jobs rejects: "We've been showing pieces of Tiger for 18 months," Jobs says, insisting that all of Apple's ideas came from within Apple. "And you can be assured all these things have plenty of patent protection," he added.

Jobs added: "Microsoft has followed our taillights for a long time. Maybe [in the '90s] we stopped innovating for a while, but now they've been copying OS X the same way they copied Mac."

With Apple scheduled to ship its new Mac OS X 10.4 'Tiger' system this week, Microsoft has chosen to demonstrate its new Longhorn OS this week at a developers conference.

Newsweek concludes the battle between the two companies to be "great theatre", adding that "the greater show by far will be the one that plays on your computer screen, making your digital life more pleasurable and productive".