At a very basic level, HostAP is simply turning a [Linux] box (with a Prism2/2.5/3 card) into an [AccessPoint Access Point]. i.e., it takes care of [IEEE] [802.11] management functions in the host computer and acts as an AP without requiring any special firmware for the wireless LAN card.

HostAP is also a complete driver for the Prism2 Chipset and will permit the card to run as an [AccessPoint Access Point], in client(managed) mode, [AdHocMode ad-hoc] mode or RFMon (Monitor) mode. 

The (http://hostap.epitest.fi/ Host AP website) has all the information you need to get it configured.
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!! Related software
(http://www.mobilnews.cz/honza/en_prog_linux_wewimo.php Wewimo) ('''We'''b '''Wi'''Fi '''Mo'''nitor) is a small script for monitoring computers connected to an access point running Linux and the hostap driver for WiFi cards. It runs as a cgi script for display in a browser.
{http://www.mobilnews.cz/honza/img/wewimo/sshot1_s.gif WeWiMo}