Is Apple letting virtual Leopards roar?

Apple will now allow versions of Leopard to be run in a virtual machine, after initially saying it would not permit users to virtualise the operating system in this way.

The Apple licensing agreement had specifically stated it was breaking the agreement if a user ran multiple versions of the server version of Leopard on a single machine, which ruled out users being able to run multiple virtual machines.

The agreement now allows users to install and use one copy of the Mac OS X Server software and install and use other copies of Mac OS X Server software on the same Apple-labelled computer.

However, while Apple is allowing users their first chance to run virtual machines on Leopard, there are some major restrictions.

The principle one is that users have to "acquire an individual and valid licence from Apple for each of these other copies of Mac OS X Server software", the Apple agreement says.

The second restriction is that it applies to users of the Leopard sever software only and not to users of the client software.

The third restriction is that it applies to users of Apple-labelled software only. Users of systems and software from PC manufactures such as Dell or Lenovo, cannot run Leopard on these systems legally.

Nevertheless, the news that Apple had relaxed the licensing limitations even slightly has been welcome by companies such as Parallels who produce virtualisation software for Apple machines.

Writing in his blog, Parallels head of public relations, Ben Rudolph, said: "[This] is a very positive step forward and indication of how we're working with partners like Apple to make life easier for hundreds of thousands of users worldwide."

But he also had a warning. "Enabling Leopard Server to run in a virtual machine may take some time," he wrote. "But we're working hard on it with Apple and will make it public as quickly as possible."

Colin Barker writes for ZDNet UK