Servers

/dev/null/nethack - http://nethack.devnull.net/
Hosts yearly tournament.

daemon.nethack.at - http://daemon.nethack.at/
Includes scoreboard and dynamic game survey.

nethack.alt.org - http://alt.org/nethack/
Overview, player and server statistics, and email support lists.

NetHack@ForkExec - http://www.forkexec.com/html/play-hack.html
Scoreboard and most frequent deaths. [Requires Java]

Nostalgia Public NetHack Server - http://nostalgia.suroot.com
Scoreboard and game playbacks. Offers Java client.

The NetHack Tournament - http://www.thenethacksite.com/nethack/
Includes top ten and past winners lists. [Requires Java]

User Friendly NetHack Server - http://nethack.notdot.net/
Quick start guide, scoreboard, and account configuration.