Also, Promise has released an Open Source (GPL) Linux driver for their line of SATA RAID controllers.
The stuff I've been posting are free hardware designs written in VHDL or somesuch (I've never tried to make use of them really). So you can probably hack at them if you know what you're doing and if you had the equipment you could produce them. It's like the source code for the hardware.
Still it's good to see more free drivers being released by the hardware manufacturers. Now that Sun's releasing the source code for this CPU, more (probably smaller) manufacturers might follow.