IE would be the poster-child for leveraging the OS. The products that leverage the OS seem to be the free ones, now - so I guess that hits a price/performance

IE would be the poster-child for leveraging the OS. The products that leverage the OS seem to be the free ones, now - so I guess that hits a price/performance sweet spot. What else is there besides IE that falls in this category? Media Player, maybe. But even though it's free and the default on windows, everyone I know has at least one other media player they use regularly (e.g., iTunes). IIS? Personally, I think IIS is quite good and can stand on its own merit. Sharepoint? I still don't understand its popularity in the corporate world, but you can't really claim it's leveraging the OS - maybe it's leveraging SQL Server? Products that stand on their own merit: MS Office (though PowerPoint looks like the one most in danger of being passed), XBox (it's not #1, but it's clearly competitive), Visual Studio (destroyed the competition) To me, it looks like Microsoft's winners by and large win by delivering a quality product, not being bundled with Windows.