"Psystar denies that said activities are unlawful and improper," the company said in its Dec. 16 response to allegations made earlier by Apple. "Psystar likewise denies the suggestion that there exists a concerted effort to commit infringement of Apple's intellectual property rights, to breach or induce the breach of Apple's otherwise unenforceable license agreements, and to violate state and common law unfair competition laws."

In November Apple accused 10 additional individuals or companies of colluding with Psystar, but didn't name names (though it said it would when it found out who they were), notes Computerworld. "Persons other than Psystar are involved in Psystar's unlawful and improper activities described in this amended complaint," Apple charged in a late November filing with U.S. District Court Judge William Alsup. "The true names or capacities, whether individual, corporate or otherwise, of these persons are unknown to Apple. Consequently, they are referred to herein as John Does 1 through 10."

Last week the clone maker said Apple "is prohibited from bringing action against Psystar for the alleged infringement of one or more of the plaintiff's copyrights for failure to register said copyrights with the copyright office as required." Psystar also claimed that Apple's Mac OS X 10.5 ("Leopard") operating system contains undocumented code designed to render inoperable personal computers that aren't running on Apple-approved hardware.

Earlier this month Apple added new charges to the federal lawsuit it filed nearly five months ago against a Florida clone maker, claiming that Psystar broke antipiracy defenses that lock Mac OS X to its own hardware.

Apple also said others besides Psystar were involved, but it didn't spell out who. In a filing dated Nov. 26, Apple amended its original suit of July after it had "discovered additional information." Among the additions is a new accusation -- that Psystar violated the Digital Millennium Copyright Act (DMCA) by dodging copy-protection technologies Apple uses to protect Mac OS X, notes Computerworld.

Psystar -- which makes and sells Mac clones -- has claimed in the past that Apple has violated Sherman antitrust rules and other U.S. laws. Psystar claims in court documents filed in U.S. District Court for San Francisco that Apple “has engaged in certain anticompetitive behavior and/or other actions that are in violation of the public policy underlying the federal copyright laws.”

In response, Apple said the defendant, Psystar, “is knowingly infringing Apple’s copyrights and trademarks, and inducing others to do the same.” Psystar makes and sells personal computers that use, without permission, Apple’s proprietary operating system software.