[ Thanks to Jason
Greenwood for this link. ]
“Those on a tight budget or unfamiliar with WLAN analyzers may
prefer to cut their teeth on shareware or open source programs.
Depending upon your needs, you may even find these programs
sufficient. We can’t hope to provide an exhaustive list, but here
are a few available shareware and open source programs to give you
an idea of what’s out there.“Administrators that don’t (yet) have officially-supported WLANs
may find that shareware stumblers are useful for on-the-cheap rogue
AP spot-checks…”