[http://www.ADMtek.com.tw ADMtek] is a taiwanese company that shook up the pricing of 802.11b silicon in the fall of 2002 with the introduction of its ADM80211 MAC/BBP.
Most all the low-end cards were using AdmTek for a good while, though RealTek now is certainly a direct competitor. Both these chipsets have semi-supported binary drivers floating around the internet for the Linux kernel.