There are two ends of an operating system: the application developers on top of the system and the underlying hardware manufactures. It’s a matter of strategy to choose between open or close. Windows opens up to both ends, while Mac OS only opens to the developers but closed on the hardware manufacturing end. 

Back in eightieth and ninetieth, it was indeed a winning strategy for Microsoft and its manufacturer partners, such as HP, Compaq, Sony, Dell, Toshiba, etc.. It dramatically brought down the price of a computer which was essential to make Windows so popular. However, having too many hardware providers also caused a lot headaches. Microsoft had to put more and more resource to design and test to make sure different hardware of different brands can all work: network cards, memory chips, graphic cards (which may be the top 1 culprit for blue screens), keyboards, mice, and nearly everything you can name. Apple was a lot “smarter”. Mac OS only works on the Mac hardware. Even after they switched to the Intel processor and geeks successfully ran Mac OS on a Dell or HP computer, Apple still didn’t open up hardware manufacture. This saves HUGE amount of time and money of Apple. It also gave people a perception that Mac OS (as well as computers which run Mac OS) is much more stable and reliable. Though Windows-based computers still out-sells Mac computers by a lot, the profit margin of Mac OS as well Mac computers must be a lot higher. 

Microsoft and Apple brought their own computer strategy into the mobile world. Since the Pocket PC days, Windows Mobile has been always open to the hardware manufacturers: HTC, Lenovo, Toshiba, Dell, HP, etc.. They produced a wide spectrum of devices: all kinds of CPUs from strongarm to snapdragon, different screen resolution, capacitive vs. resistive screen, slide out vs. blackberry-like keyboard, different layout of QWERTY keyboards, MicroSD card vs. built-in flash memory, all kinds of batteries, cameras and audio jackets. However, Apple’s iPhone OS series only has one screen resolution: 320x480 portrait, although they have recently added one more resolution: 1024x768 (for iPad). This must have saved HUGE amount of time and money for Apple. That may also contribute to why Apple’s stock went up from less than fifty to now nearly three hundred in the past five years while MSFT has been stuck around twenty something. 

We all see how many iPhones are around us, although none of them has any kind of physical keyboard, changeable battery or MicroSD slot. The strategy which helped Microsoft win in the PC market eventually will probably make Microsoft loser in mobile world.