By Aidan Malley

Published: 06:10 PM EST

Itself attacked for allegedly violating Apple's licenses, Psystar made offense its best defense on Tuesday when it filed a countering lawsuit in federal court, accusing the Mac maker of unfairly squeezing out possible rivals.

A statement from custom PC builder Psystar rejects the basis for Apple's complaint, which asserts that Psystar's OpenComputers violate the Mac OS X end-user license by running the software on non-Apple hardware. The firm instead argues that it's Apple breaking the law through the terms of the agreement in question.

By insisting that its software be tied to its hardware, Apple is violating pro-competition laws that include the Clayton Antitrust Act and the Sherman Antitrust Act, Psystar claims. Apple is characterized as a monopoly-like entity, abusing its copyright to guarantee its position as the only authorized PC maker for the operating system.

Since Psystar began selling what are effectively Mac clones as of April, the Florida-based company has repeatedly challenged Apple and insisted that Apple is deliberately ratcheting up the prices on Macs knowing that there was no real alternative for running its operating system, although Psystar has never elaborated on this perceived cost difference.

While the plaintiff in the new lawsuit intends to negate the restrictive clauses of the Mac OS X license as well as obtain damages, company chief Rudy Pedraza tells CNET that the goal is simply to make non-Apple Mac OS X systems a possibility rather than forcing complete access to the platform.

"What we want to do is to provide an alternative, an option," he says. "It's not that people don't want to use Mac OS, many people are open to the idea, but they're not used to spending an exorbitant amount of money on something that is essentially generic hardware."

Apple has kept to its traditional silence regarding lawsuits, but in this circumstance won't have that option for much longer; the California-based electronics designer is legally required to respond to Psystar's complaint within 30 days.

Simultaneously, Psystar has no intentions to reverse course even after the threat of an Apple lawsuit intimidated what's allegedly a small portion of its customers. In addition to the OpenComputer and the more recent OpenServ, Pedraza's company is planning a portable computer that would also support Mac OS X through unofficial, community-sourced methods.