Apple has sued Psystar, the computer maker that in April started selling Intel-based systems with Mac OS X pre-installed, for copyright and software licensing violations, according to court records and a Florida attorney.

A Psystar employee who answered the company's telephone Tuesday morning and identified himself only as "George," said that the company had no comment on the lawsuit.

Although the full complaint has not been posted to the federal court system's electronic document system, Apple filed charges on 3 July, a search of the system revealed.

According to Jorge Espinosa, a Miami-based lawyer who specialises in intellectual property law, Apple's lawsuit charges Psystar with violating its shrink wrap license, as well as with trademark and copyright infringement. "Psystar has been manufacturing and selling a line of computers which sell pre-installed with Apple's OSX operating system," Espinosa noted in an entry to his blog. "Apple's shrink wrap license which comes with OSX specifically requires that the software be installed only on Apple branded computers."

Questions about Psystar's practice of selling its Mac-like machines - initially named "OpenMac," but quickly changed to the more neutral "OpenComputer" - with Apple's Mac OS X 10.5 "Leopard," operating system, arose as soon as the company touted its $399 (£199) clone.

The end-user licensing agreement, or EULA, for Mac OS X expressly forbids users from installing the operating system on hardware not sold by Apple. "You agree not to install, use or run the Apple software on any non-Apple-labelled computer, or to enable others to do so," Apple's EULA reads.

In April, a Psystar worker was quoted by Informationweek as saying that the company thought the ban might not hold up to a legal challenge. "What if Honda said that after you buy their car, you could only drive it on the roads they said you could?" said the spokesman, who identified himself only as Robert.

Later that day, however, Psystar declined comment when asked by Techworld's sister publication, Computerworld, to elaborate on its legal position.

The lead attorney for Apple in the case, James Gilliland of the San Francisco law firm of Townsend and Townsend and Crew, declined to comment today on the filing. Apple's spokeswoman did not immediately reply to a request for comment.

Psystar sells several Mac-ready computers, including desktop systems priced at $554.99 with Leopard pre-installed. Last month, the company started selling knock-offs of Apple's Xserve servers, pricing its version 12.5 percent under Apple's list price.

It's unclear what impact a win by Apple would have on Psystar's current user base, but it would presumably stop Psystar from issuing updates to the tweaked version of Mac OS 10.5 it adds to its machines.

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