Before you get too excited about the 100 or so patents owned by the OIN, keep in mind that Microsoft owns literally thousands of patents. It won't reveal the specific ones being infringed because it figures that free and open source software advocates will begin filing challenges to them. All of which raises the question: is Microsoft itself infringing software patents?

The deal hammered out in November of last year between Microsoft and Novell hints at that possibility. The two companies agreed not to sue each other's customers for patent infringements, then worked out complicated revenue and marketing collaboration deals that included a $108 million "balancing payment" from Microsoft to Novell to cover patents.

Both Novell and Microsoft were mum at the time about whether the deal indicated that any patents were infringed. David Kaefer, the director of business development for intellectual property and licensing at Microsoft, said that "For the same reasons that Novell will not say if there are any Microsoft patents they infringe, Microsoft is not going to come out and admit that it has a set of products that infringe Novell's patents."

So is Microsoft vulnerable in court? At the end of the Fortune article, Steve Ballmer was asked if his company would sue its customers for royalties if it really came down to the wire. "That's not a bridge we've crossed," he replied, "and not a bridge I want to cross today on the phone with you." To me, that sounds like neither money nor principle are on the line, but market share; it's the kind of response you would expect from someone who can't afford to lose goodwill.

The larger point is that Microsoft was hoping to do deals similar to the one it made with Novell with other large open source software distributors, such as Red Hat. Indeed, Ashlee Vance of The Register thinks the whole point of the piece in Fortune was "to remind Red Hat that it will need to go ahead and strike a deal like Novell." As Vance correctly pointed out, however, Red Hat may not be the company Microsoft should worry about most when it comes to open source software. "Close partners such as IBM and HP - companies with more than ample patent portfolios - would not sit idly by as Microsoft tried to derail their lucrative Linux server businesses." And it's knowing just how convoluted a set of mutually-assured-destruction patent lawsuits could get that will keep this from ending up in the courtroom.