Sentence:  Oddly, the big difference didn't come in our user ratings, where we expected the famously friendly <WSD>Mac</WSD> interface to shine. / Apple's popular commercials have painted the picture in stark terms: There are two types of people, <WSD>Mac</WSD> people and PC people. 
Meaning of the word marked with <WSD> tags:  A Macintosh computer (made by Apple Inc.), or its operating system.