I'm a big proponent of interoperability in the computing world. To be completely frank, anyone who isn't in favor of interop is either a monopolist, or dumb. Apple has realized this quite well here in age of OS X, most recently made apparent with the launch of Boot Camp, a tool for running Windows XP on your Mac.
So it is with pleasure that I spread the word about Port 25, a Microsoft blog detailing the goings-on at the Microsoft Linux Lab. This lab was established by Microsoft for the purposes of achieving better interop with other operating systems, something they're currently catching a lot of hell for over in Europe.
It's a great sight to see when massive companies like Microsoft are not only working on interoperability, but actually publicly endorsing it. As has been pointed out, the questions Microsoft certification exams assume a nearly-homogenous Microsoft environment, which is almost never the case.
The admittance by Apple and Microsoft that their competitors' products will occasionally be selected over their own is a good step towards eliminating the absolutist culture in the computing business world. The American political system has shown us just how asinine this absolutism can get (just read the blurbs on the DNC's homepage), so any step we take away from that quagmire is applaudable, in my opinion.