One of the reasons Windows won was by being open to developers. It was pretty common back in the days for OS vendors to put a price on the SDK. And Linux was just starting.
Linux is friendly on the server side, but on the client side there are many things lacking.
"One of the reasons Windows won was by being open to developers. It was pretty common back in the days for OS vendors to put a price on the SDK"
Until recently, Windows development more or less required commercial development tools costing hundreds of dollars; how is that any different?
Even now, the free Microsoft tools are much more limited than their for-pay counterparts and if you use tools outside of the ones Microsoft provides, you risk lack of support, incompatibility and less-than-seamless integration with operating system features.
Windows, and MS-DOS before it, were vastly more open to development than competing platforms. Microsoft and Borland's development tools weren't free, but they were cheap. MSDN subscriptions didn't start becoming a significant revenue source for Microsoft until well after its monopoly status was assured.
