I don't think you were implying that all other operating systems were catching up, just most of them. For example, Solaris has had a stable driver DDI (Device

I don't think you were implying that all other operating systems were catching up, just most of them. For example, Solaris has had a stable driver DDI (Device Driver Interface) for years. This is what allowed ISVs to write drivers for ancient versions of Solaris that still work today (assuming the base hardware platform is still supported). That's also what allows the latest versions of the nVidia driver to generally just work on different releases of Solaris.