# X11
X11 is a GUI of NetHack, mainly used on unix-type operating systems. If your copy of NetHack has that compiled in, you can enable it by setting OPTIONS=windowtype:X11 in your config file.

Wikipedia has an article about:
X resources

 Character selection dialog
 Without tiles or any X resources.
 Running on Kubuntu Linux 6.06.
X11 can do both tile-graphics and ASCII.
If you do not have any X11 resources set for NetHack, all windows will be black text on white background, and this makes playing almost impossible, unless you turn off color. 
You can define the X resources in a text file, for example NetHack.ad in the playground or ~/.Xdefaults, with one resource per line. You can then use xrdb -merge ~/.Xdefaults to make the resources active for your X session.
The configuration file that comes with NetHack sources, win/X11/NetHack.ad, contains extensive documentation about the file and what you can change in it. This file is copied to the nethack playground when compiling and installing from source.
List of some of the X resources NetHack accepts:

Resource string
Value
Explanation

NetHack*font
font
Sets the font for all NetHack windows. Must be fixed-width font!

NetHack.tile_file
filename
What file contains the tiles used for the map? The file must reside in the NetHack playground. If NetHack was compiled with USE_XPM, then this can be a normal xpm-bitmap, otherwise it must be NetHack's custom format.

NetHack.pet_mark_bitmap
filename
File to use to annotate pets in tile mode. Same restrictions as with tile_file above, except this one must be a two color, black and white, image; the white will be transparent and black will be replaced with pet_mark_color, see below.

NetHack.pet_mark_color
color
Color of the pet annotation mark.

NetHack*message_lines
number
The number of lines the message window will show without scrolling.

NetHack*message_line
boolean
If True, the message window has a line that separates old and new messages.

NetHack*autofocus
boolean
If True, force keyboard focus to attach to popup windows.

NetHack*slow
boolean
If True, the default, a popup for single character prompts such as y/n is not used.

NetHack*background
color
Sets the background color of all NetHack windows

NetHack*foreground
color
Sets the foreground color of all NetHack windows

NetHack*map*background
color
Sets the background color of the map

NetHack*map*black
color
Sets the color 'black' in map to some other color

NetHack*map*red
color
Sets the color 'red' in map to some other color

NetHack*map*green
color
Sets the color 'green' in map to some other color

NetHack*map*brown
color
Sets the color 'brown' in map to some other color

NetHack*map*blue
color
Sets the color 'blue' in map to some other color

NetHack*map*magenta
color
Sets the color 'magenta' in map to some other color

NetHack*map*cyan
color
Sets the color 'cyan' in map to some other color

NetHack*map*gray
color
Sets the color 'gray' in map to some other color

NetHack*map*orange
color
Sets the color 'orange' in map to some other color

NetHack*map*bright_green
color
Sets the color 'bright_green' in map to some other color

NetHack*map*yellow
color
Sets the color 'yellow' in map to some other color

NetHack*map*bright_blue
color
Sets the color 'bright_blue' in map to some other color

NetHack*map*bright_magenta
color
Sets the color 'bright_magenta' in map to some other color

NetHack*map*bright_cyan
color
Sets the color 'bright_cyan' in map to some other color

NetHack*map*white
color
Sets the color 'white' in map to some other color

'boolean' can be either True or False.
'color' can be defined either with a named color, or a hexadecimal RGB number, such as #00ff00.
'font' can be any font string the X11 server knows about. Use xlsfonts or xfontsel or some such program to see the fonts.
Some good values would be, for example

! Lines beginning with&nbsp;! are comments and are ignored.
NetHack*font:                   vga

NetHack*background:             black
NetHack*foreground:             grey

NetHack*map*background:         black

NetHack*map*black:              grey25
NetHack*map*red:                red3
NetHack*map*green:              green3
NetHack*map*brown:              DarkOrange3
NetHack*map*blue:               blue3
NetHack*map*magenta:            magenta3
NetHack*map*cyan:               cyan3
NetHack*map*gray:               gray70
NetHack*map*orange:             yellow
NetHack*map*bright_green:       green
NetHack*map*yellow:             yellow
NetHack*map*bright_blue:        blue
NetHack*map*bright_magenta:     magenta
NetHack*map*bright_cyan:        cyan
NetHack*map*white:              white

This page may need to be updated for the current version of NetHack.
It may contain text specific to NetHack 3.4.3. Information on this page may be out of date.
Editors: After reviewing this page and making necessary edits, please change the {{nethack-343}} tag to the current version's tag or {{noversion}} as appropriate.