Apple's broad cross-licensing agreement with Microsoft has been common knowledge for over a decade, but we've been able to extract some previously unknown details of the agreement from today's testimony in the Apple v. Samsung trial. Apple's director of patent licensing and strategy, Boris Teksler, testified that while the licensing agreement between the companies broadly covers technical and design patents, it does still provide some protection against verbatim copying of products in the form of an "anti-cloning" provision. Teksler specifically stated the following:
"The Apple and Microsoft cross-license does cover the design patents. However, we took special prohibitions from both parties so there is what I term an 'anti-cloning' provision... so we couldn't copy each other's products. There's a clear acknowledgement that there's no copying."
The 1997 cross-licensing agreement
We've been able to locate the anti-cloning provisions in the original 1997 cross-license agreement between Microsoft and Apple. While newer agreements may exist between the two companies, it's fair to assume the specifics of such protection against copying would be at least similar.
First of all, the inked deal does in fact encompass worldwide patent coverage on both technical software features (utility patents) and aesthetic hardware and software elements (design patents).
The specific provision prohibiting such cloning further makes it clear that functionality and user experience, as well as the physical form factor for products, were expressly considered in the deal. With that said, the outlined prohibition on copying appears to be focused on the products and interfaces as a whole, not on isolated features like Apple's patented bounce-back scrolling. It's likely those types of smaller UI features are just included under the general licensing terms and can be freely copied.
"Identical or substantially identical"
The broad scope of this language means that Microsoft can't provide a product that simply clones the user interface and hardware of Apple's iOS devices. Similarly, Apple would be unable to mirror the unique UI of Windows 8, or perhaps the new Surface tablet hardware. However, the bounds of these protections aren't defined with absolute clarity. For instance, the anti-cloning language from the 1997 agreement prohibits only those products "identical or substantially identical" to the other company's technology. What exactly constitutes a "substantially identical" interface or product? Who knows, but you can just imagine the number of holes a group of lawyers could poke through that bit of legalese.