To be more specific, according to Motorola, Microsoft is infringing on 16 patents on products ranging from Microsoft Exchange, Windows Marketplace to Bing Maps. According to the suit, even the Windows operating system infringes on some Motorola patents. The actual plaintiff in the case is the soon to be spun off Motorola Mobility, the cell phone producing arm of the company which is led by CEO Sanjay Jha.
Not content to let the legal papers speak for them, Motorola felt compelled to explain why the company is taking Microsoft to court. Kirk Dailey, corporate VP for intellectual property at Motorola said, "It is unfortunate that Microsoft has chosen the litigation path rather than entering into comprehensive licensing negotiations, as Motorola has mutually beneficial licensing relationships with the great majority of technology companies industry-wide."
source: Motorola via Engadget