The concept of a NetHack bot, meaning a computer program which plays NetHack without human intervention, is often brought up in RGRN. Most conversations conclude that a bot is in theory possible, but tremendously difficult.
There exists a simple perl script which is used by pudding farmers to automate the process of offering, praying, and clearing messages.
It is also possible to copy and paste a list of commands into a NetHack window which will repeat the same process over and over again. This was first used by eit_brad to achieve a high score which overflowed NetHack's signed 32-bit score variable in the 2003 /dev/null Tournament.
A true bot with an internal model of the game, capable of making reasoned decisions about game events, and ultimately capable of ascending, remains elusive.
Heres something worth looking at: http://taeb.sartak.org/