Linuxant – DriverLoader for Wireless LAN devices strives to bring the very latest Wireless LAN technology to the Linux community. It's a compatibility-wrapper allowing standard Windows NDIS (Network Driver Interface Specification) drivers shipped by hardware vendors to be used as-is on Linux x86 systems.

That is the solution to support devices for which no adequate native open-source drivers are available. Very famous chipsets such as the hyped Centrino hardware or even WLAN 802.11g chipsets in cards like my Truemobile 1300 are not yet supported by the hardware vendors – 6 months or more after chipset release.

Linuxant probably didn't manage to get hardware vendor license their stuff, so you need to buy their DriverLoader for $19.95 as noted here

They have quite a strange way of loading the windows NDIS drivers via a local webserver, mounted at port 18xxx that is open where you have to provide your root password – not just a very bullet-proof way I guess.

Anyhow – a list of supported chipsets is :

Broadcom – Chipsets:

• Belkin : F5D7000 F5D7010
• Buffalo : WLI-CB-G54 WLI-CB-G54A WLI-PCI-G54
• Linksys : WMP54G WPC54G
• Microsoft : MN-730 MN-720
• Compaq : Presario 2100/2500/3000
• Dell : TrueMobile 1180 (BCM4301 – 802.11b) TrueMobile 1300 (BCM4306 – 802.11b+g) TrueMobile 1400 (BCM4309 – 802.11a+b+g)
• eMachines : M5310
• Fujitsu : N-Series/E4000D/P5000D/S2000/S6000D
• Gateway : 400/450/600 Series
• HP : Pavillion XF/ZD/ZE

Intel – Chipsets:

• Acer : TravelMate 800 Notebook with Intel PRO/Wireless LAN 2100

Realtek – Chipsets:

• D-Link : DWL-510
• NETGEAR : MA521

Atheros – chipsets:

• Linksys : WPC55AG
• NETGEAR : WG311

another how-to for installing the driver can be found here