http://www.concoctedlogic.com/digfe/

From the homepage:

Digfe is a free, GUI interface or 'front end' for the dig program.
Dig is a dns client, distributed with ‘bind’ – the named daemon for
Linux / Un*x , NT/2000, VMS, AIX, and just about every other box on
the planet.

Digfe is being written in Visual Tcl 1.6.0a1.