Original sentence: Interestingly, Apple's iTunes software now has the capability to convert WMA files to AAC.March 21, 2000) by Microsoft and Microsoft has invoked its patent against VirtualDub, a free video conversion program.The ASF container structure is patented in the United States (United States Patent 6,041,345 Levi, et al
Edited sentence: Interestingly, Apple's iTunes software now has the capability to convert WMA files to AAC , which Microsoft may have overlooked, but more likely Apple secured a contract.March 21, 2000) by Microsoft and Microsoft has invoked its patent against VirtualDub, a free video conversion program, which wasn't even marketed.The ASF structure (the container, not some codec algorithm) is patented in the United States (United States Patent 6,041,345 Levi, et al.The reason why they invoked the patent was the control over the content which they have without other programs being able to read ASF