Microsoft received an outpouring of support last week from big-name companies, including Apple, Facebook, Google, Hewlett Packard and Intel, in its patent battle.

The companies asked the U.S. Supreme Court to honor Microsoft’s request filed in August for a ruling to make it easier to invalidate an issued U.S. patent. Should the U.S. Supreme Court hear Microsoft’s case, the landscape of patent litigation could be historically reshaped, according to the non-profit digital rights group Electronic Frontier Foundation.

If successful, the EFF said, current law would have to be revised to lower the standard of proof to show a patent is invalid. According to an EFF statement: “In court, parties have to prove their case by some ‘standard of proof.’ In almost all civil cases, the standard is ‘preponderance of the evidence,’ meaning it is more likely than not that the facts are true.

“When the question is invalidating a patent, however, the U.S. Court of Appeals for the Federal Circuit decided that a defendant trying to prove a patent invalid must do so by a higher standard than normal civil cases, that of ‘clear and convincing’ evidence.”

“Clear and convincing” means that the facts are “highly probable,” which is a much more difficult standard to prove than preponderance, the EFF said. It showed support for Microsoft’s request with its own “friend of the court” brief, alongside non-profit entities the Apache Software Foundation, the Computer & Communications Industry Association, and the Public Knowledge Project.

A 2009 patent infringement case prompted Microsoft’s request after a district court found the software giant guilty of infringement and awarded US$290 million to Canadian software maker i4i. The court agreed with i4i that Microsoft violated its patent, which covered editing documents containing markup languages such as XML. Microsoft Word 2003 and subsequent versions used XML editing capabilities.

However, Microsoft argued during the case that “i4i’s patent was invalid because the disclosed invention had been embodied in a software product sold in the United States more than a year before the patent application was filed,” the EFF said.

John Thorne, deputy general counsel at Verizon, which supported Microsoft alongside Google and Dell, said, “For the whole high-tech community, this issue of bad patents being asserted by trolls is a huge issue. More patents are issuing, products are getting more complicated, and lawsuits are increasing.”

It is still uncertain if the Supreme Court will take the case, since it narrowly resolved software patent validity issues earlier this summer with its decision in the Bilski case.