NScan.org: the legend is still here ;)

DIG is a TCP-based DNS client that supports most of the available options, including AXFR zone transfer. It has two operation modes - traditional and extended. In first mode it asks address or host name by the default means of Windows sockets. In extended mode it utilizes TCP connection to acquire any info that can be supplied by server, including AXFR (complete transfer of the entire zone). TCP ensures reliable data connection and full data set from server (default UDP answer data amount is limited to packet size). Received data may be saved to text file without extra operations.

DIG supports 20 different queries to nameserver, which are shortly described in drop-list. Default operation mode is extended, but if no server selected, host will be looked up by Windows sockets. In case none of the DNS servers are known, DIG has default pre-defined root server list.
WARNING: root servers contain only authority information and can't be used in regular lookup purposes - it's only a starting point for domain information discovery.
List of the root servers may also be found at ftp://rs.internic.net