In November, Microsoft and Motorola (now owned by Google) made their cases in a Seattle-based US federal court in a long running legal battle over three patents owned by Motorola. Today, the judge in the case threw out 13 of the patent claims that Motorola claimed Microsoft violated.
CNet reports that Judge James L. Robart agreed with Microsoft's lawyers that Motorola's patent claims that concerned the encoding and decoding digital video content were in fact invalid, thanks in part to a previous US patent law. In very basic terms, the judge ruled that Motorola's patent claims were "indefinite", which means Motorola didn't do a good enough job in explaining their patents.
Not all of the patent claims Motorola has against Microsoft have been invalidated yet. Even if the judge rules in Motorola's favor in the remaining claims, there's still the matter of Microsoft's payment to Motorola for those patents. Microsoft's position is that Motorola should offer those patents under "fair, reasonable and nondiscriminatory terms", otherwise known as FRAND. If the judge rules for Microsoft in this aspect of the case, that means Microsoft would have to pay a fraction of the money that Motorola is asking from Microsoft.