It depends on what you mean by 'driver'. FUSE has certainly created a portable set of filesystem drivers for several operating systems. There are also things li

It depends on what you mean by 'driver'. FUSE has certainly created a portable set of filesystem drivers for several operating systems. There are also things like ndiswrapper and project evil to wrap windows network drivers for various unixy systems. The real reason that most drivers don't get ported seems fairly obvious though. Different systems expose different amounts of surface area, different programming models, etc. Why is the current standard of tight coupling bad? Gains in portability are generally offset by a loss in performance, which isn't really something you want on your root filesystem or your graphics card (or your server's NIC, as a counterbalance to ndiswrapper).