From: http://www.uq.edu.au/~cswallis/nhqt/

NetHack QT - What is it?

NetHack is a Free graphical one-player roleplaying game with a
highly modular window system interface supporting TTY, VGA, Mac,
Amiga, and other displays. Qt is a graphical user interface toolkit.
So, "NetHack with Qt interface" is a version of NetHack which has
a user interface module written using the Qt toolkit.

How is it better than the plain X11 interface?
The Qt interface has these extra features: 

o   Tiles (graphics) in the inventory and other item-menu windows. 
o   The player cursor changes colour as your relative hit-points drop. 
o   The message window greys-out older message. 
o   The item menus allow a count (click to left of icon - hidden feature). 
o   Icons for the major attributes and player states. 
o   Menus (only needed by newbie dungeon fodder). 
o   Variable size fonts and tiles. 
o   More space for the map as messages and status are side-by-side. 
o   You rarely need to put the mouse in a pop-up to interact with it. 
o   Macros - hidden feature - F1=multi-rest F2=multi-search F3=try-it 
o   It is much easier to code, so new feature-requests are more easily done. 
o   Sound support.

The standard NetHack X11 interface is written in C using the Athena
Widgets toolkit. The strongest reason for doing it that way was
that NetHack is one of the most incredibly portable programs of
any kind, and the Athena Widget Set is also available for free on
a large number of X11 implementations. The problem is that Athena
Widgets (also known as Xaw) is very ugly, difficult to program in,
and buggy. The Qt interface toolkit on the other hand is written
in C++ and is freely portable to any X11 implementation, but is
less widespread, making it inappropriate for the standard NetHack
X11 interface.

Sound support

The QtNetHack patch includes experimental support for sounds to be
played based on messages. For example, you can arrange for a gong
to sound when the message "... cursing shoplifter..." appears. The
system maps any regular expression (can be just some text) to a
sound. The QtNetHack windowport is the only one providing this
method, and it does so using the NAS (Network Audio System) . As
distributed, the patch enables this feature - see include/config.h
once you have applied the patch, and look for USER_SOUNDS for an
explanation of how to disable it if you want to.

You will also want to collect some sound samples to try it out,
and a .nethackrc attaching them to messages. This package contains
the .au files that I use, and my ~/.nethackrc. Many of the sounds
are from the nhsound package, which you can find referenced on the
NetHack Home Page.