If you follow the &quot;API war&quot; hyperlink, it&#x27;s under the heading &quot;It&#x27;s Not 1990&quot;.<p>When consumers are upgrading their hardware regularly as they were in the 1990&#x27;s, then developers can disregard the notion of users &quot;upgrading&quot; their software.<p>Instead they can just write applications targeting new hardware.  It does not have to run on older hardware.<p>The user will be compelled to upgrade the hardware and, in the case of Windows, by default they get the new software.  The example cited was Excel versus Lotus123.<p>MS also benefitted from hardware sales through agreements with the OEM&#x27;s.