RUT (pronouced as 'root') mean 'aRe yoU There'.

It was developed to brute force its way into wvlan (IEEE 802.11b)
access points which use mac authentification.

It offers a wide range of _local_ network discovery features like arp
lookup on all hosts on a network with vendor-string, spoofed DHCP
request, RARP, BOOTP, ICMP-ping and address mask request and some
other features.