In its final push before presenting arguments to the U.S. Supreme Court, Microsoft filed a legal brief late today arguing that the court shouldn't require it to offer "clear and convincing evidence" to overcome the traditional presumption that patents approved by the U.S. Patent and Trademark Office are valid.

The filing comes just 11 days before Microsoft and i4i, a tiny Toronto company, presents arguments in a hearing at the court. That hearing is likely the last opportunity Microsoft has to defend itself against a $200 million judgment that held that the company infringed on i4i's patents.

The response brief attempts to rebut i4i's claims that Microsoft should be held to the "clear and convincing" standard. Microsoft wants the court to apply the lower preponderance of the evidence standard, which would make it easier to invalidate i4i's claims.

"i4i's argument rests on a distorted view of (the Patent and Trademark Office's) examination and reexamination procedures," Microsoft argues in its filing.

The dense legal argument aside, options are thinning for Microsoft. i4i filed a suit in 2007 claiming that Microsoft violated one of its patents covering the way the software giant used XML, or extensible markup language, in its Word program. After losing the original case, Microsoft appealed and lost that case as well. The company filed an appeal with the Supreme Court, which agreed to hear the case last November.

More than just a debate over a specific piece of technology, the case is becoming something of a bellwether for patent litigation in technology. Companies, investors, academics, and even the government are taking sides, realizing that the ruling will set a precedent under which technology companies will have to live for years. Microsoft rivals and partners, such as Google, Apple, Intel, Hewlett-Packard, and Facebook, among others, filed a friend-of-the-court brief supporting Microsoft. Their fear is that a ruling against Microsoft will encourage more small companies to come out of the woodwork, pushing patent claims against large companies.

i4i has lined up its own friend-of-the-court briefs supporting its claims, including venture capitalists, universities, and, most notably, the U.S. government.

The case is just one piece of Microsoft's effort to reform patent law. In February, Microsoft general counsel Brad Smith and deputy general counsel Horacio Guitierrez laid out Microsoft's goals for giving the Patent and Trademark Office the resources it needs to "improve patent quality and continue its efforts to tackle the enormous backlog it faces."