There are significant benefits that Linux has derived from its lack of a stable driver ABI. For one example, adopting the AMD64 architecture proceeded signific

There are significant benefits that Linux has derived from its lack of a stable driver ABI. For one example, adopting the AMD64 architecture proceeded significantly faster on Linux systems because nobody had to wait for binary drivers to become available, thus enabling end users to use their shiny new hardware to the fullest extent. For another, do you believe that the effort to add real-time capabilities to Linux would have any chance at all at succeeding while being constrained by stable internal ABIs? Basically only GPU drivers are sufficiently complex that the vendors are actually concerned about protecting their IP investment there and release only binary drivers; though AMD has even figured out recently that they can open source the kernel part of their GPU driver since all the interesting stuff is happening in user-space. Are driver ABIs of other kernels actually stable across major versions, in all cases? Another comment of yours says this is not the case. One major difference here is that there's a new release of Linux with substantial new features every 3 months, whereas new releases of NT come out every 3-6 years, and the gap is even larger for Solaris. Another major difference is that the upstream Linux kernel doesn't have paying customers; products like RHEL and SLES do, and maybe that is the level at which things like driver ABI guarantees should be provided, if there is actual demand for it.