Modifications and Add-Ons

Auto-NetHack - http://auto-nethack.sourceforge.net/
Version 3.4.3 configuration utility. News, usage notes, and source.

Bertelli's Place - NetHack Patches - http://www.dorineleil.pop.com.br/bertelli/share/index.en.html#nethack
For version 3.4.x: Whips, Bard, Monk Flying Kick, and Wizard Staff.

Hearse - http://www.krollmark.com/hearse/
Windows utility to exchange bones files with other players.

Jukka's NetHack Modifications and Utilities - http://www.netsonic.fi/~walker/nethack.html

NetHack Additions - http://www.multifoliate.com/nh/
Heck^2 patch, Abigaba tileset, and a random horribly drawn cartoon.

nethack-el - http://www.nongnu.org/nethack-el/
Version 3.4.1 as an emacs major mode. News, screenshot, and source.

PatchHack - http://patchhack.sourceforge.net/
Mild variant collecting various authors' patches.

Stan's NetHack Page - http://nh.gmuf.com/
Patches, utilities, and related links.

Unix Hearse - http://www.argon.org/~roderick/hearse/
Utility to exchange bones files with other players for Linux and similar systems.

YHACS - You Hear A Clicking Sound - http://xoomer.alice.it/pid/
Sound theme for Windows. Requirements, installation directions, and sample files.