Yes, Microsoft maintains tons of legacy support for user's running old software on newer platforms - but that's essentially support for their own legacy platfor

Yes, Microsoft maintains tons of legacy support for user's running old software on newer platforms - but that's essentially support for their own legacy platforms. They don't go out and provide tools for say, pre-OSX Mac users to get the latest Microsoft Office. Chrome Frame is essentially software that runs on top of Microsoft's legacy, deprecated browser and allows it to have modern functionality. As the post points out, Google Chrome does have features similar to what you describe to allow backwards-compatibility with legacy sites that need an old browser. That's not this.