Broadcom releases an open-source driver for its wireless chipsets

Atheros Madwifi (and related) had their own administrative interfaces for managing the drivers and card. The traditional Linux 'iwconfig/ifconfig' stuff was not useful for the advanced features that Atheros supported in their drivers.

It was not until very recently until Linux 'iw' and cfg80211 interface has reached something that closely approximated the functionality provided by Madwifi.

One of my favorite examples is how with 'iw' and 'madwifi stuff' you can setup your wifi card to be multiple virtual wifi cards. That is you can use one card to do something like simultaneously sniff network traffic while still attached to a access point. Your still limited by the hardware to one frequency, but it's still useful.