MacNightOwl has an interesting article about the history of Mac OS licensing with Microsoft, the clones, and why Apple has everything to lose by licensing Mac OS X.
“The second issue is one of compatibility. By having to test its operating system for a relatively small number of systems, Apple can build its operating systems faster and with greater reliability. One of the huge problems Microsoft confronts regularly is that its products must run on tens of thousands of possible configurations. They are forced to hire more quality control people, and it takes far longer for them to release major Windows upgrades. And that doesn’t even consider a less efficient development environment.”
Read the entire article over here.