By the way, add Realtek and Ralink (now Mediatek) to the above list of companies writing drivers for Linux.

And now name a wifi chipset that isn't made by one of these companies. :-)

It's awesome that Linux has achieved this kind of support. But this is a luxury. Don't take it for granted. It took a long time and a lot of energy to get there. These companies are still keeping hardware docs under NDAs so it is very hard for other open source systems to compete fairly.