I asked around, and I was told that the sole source requirements only apply to contracts for people to perform work. Software and Hardware do not fall into those rules since by nature software can (ultimately) only come from one vendor. If there were sole source requirements for hardware and software Apple would have a hard time getting their stuff in because you can only get the hardware from them (just to even get to the software).
Yeah, diamond.g, that's right. When it comes to, say, toothpicks for the Pentagon break rooms, you could reasonably apply sole-source requirements to that contract. But when it comes to OTC Zyrtec (an allergy medication) for the on-site clinic, Zyrtec is still protected by a drug patent, there is no generic, only one drug company can make it, it has unique, desirable qualities that differentiate it from other such products, Defense can, for now, only go to one manufacturer to procure it. To make Defense meet sole-source requirements for Zyrtec might mean, subject to interpretation of the unique benefits of the drug, Defense can't get Zyrtec for its clinic.
That's a goofy analogy, but I wanted to take it out of the realm of computer technology. The point is, of course, *an* operating system can run PCs, *the particular* operating system can run particular software on a certain class of PCs. Actually Apple would be far more shutout of Defense sales if sole-source requirements were applied to existing product as well as the product of certain kinds of labor. At least Windows will run on PCs from numerous vendors; Mac OS X will only run on PCs from one vendor.
Defense runs Windows, Linux and OS X as need requires. The overwhelming majority of OS software in use at Defense is Windows. As Windows established itself as the de facto standard in desktop computing operating systems, this only makes sense. The nature of my education and profession, I've never need use anything but a Mac. At this point, I never would; I don't even use Boot Camp; I won't even buy another vendor's WiFi product now, I've had such problems with poor quality of expensive third-party products, even for my limited needs. I love my Mac, its OS and my other Apple gear and software. But I still wouldn't want to pay via my income tax for Defense to reevaluate their OS of choice and replace all those PCs with Macs running OS X, nor would I even want to pay for the resources, training and support to convert all those existing PCs to Linux. There is better use at Defense for that money.