Atheros is a manufacture of 802.11 chipsets that are used by over 30 different wireless device manufacturers, including Netgear, D-Link and Linksys.
Just recently a totally open driver for these devices that talks directly to the hardware layer came into existence. Prior there was a partially open one in which operation out of the ISM/UNII bands was one of the developed features.
The real question now that this dam has been completely burst is what else can be done? Some hams wonder if they can be coded to handle doppler shift so that they could be used in conjunction with future AMSAT projects.
More info:
http://www.qsl.net/kb9mwr/projects/wireless/modify.html