Only for hardware. Typically for wireless and video drivers. If you use an Intel video card and Intel wireless (the former of which you can only do if you don't

Only for hardware. Typically for wireless and video drivers. If you use an Intel video card and Intel wireless (the former of which you can only do if you don't care for intensive 3D apps) then you can get away with no OS level proprietary software. Pretty easy to do if your only use of the machine is development work. Once you get into gaming you have to pile a ton of proprietary software (OS and otherwise) if you want to play anything recent.