The hardware: ethernet Only a few recalcitrant vendors remain closed. ethernet 95% documented 99% working Open documentation largely due to the effort of one man: Bill Paul Industry is so competitive that vendors often supply documentation before chips are available! Notes: Broadcom does not release documentation (but helps fix drivers) Marvell is being dragged open kicking and screaming Sun/Apple "gem" and Sun "cassini" are not documented Intel only recently opened up their em/fxp documentation Good news: At the moment, most 10 Gigabit chipsets are open Everything else is open!