Xorg is the default X Window server since Debian 4.0 (etch). It replaces XFree86 and is maintained in Debian by the XStrikeForce. For Debian 10 and later, the default human interface protocol is Wayland.
Xorg version numbering has changed since xorg 7.0. Nowadays, Xorg is released with a version number (like 7.4). This release is composed of various modules which have their own version number (each module started at version "1.0" when Xorg 7.0 development cycle started). For instance, Xorg 7.3 was shipped with Xserver version v1.4, xf86-input-evdev v1.1.5, xf86-video-intel v2.1.1, etc.. If you want to learn more about Xorg releases/versions, see this blog.
Debian version number follows upstream convention. The module's version may be different (The maintainers sometimes cherry-pick more recent and stable modules). Reminder: Debian package version sometimes starts with a digit followed by a column, like 1:7.3.1-2. That part (1:) is Debian-specific. Also, anything after the dash (-2) is the Debian packaging version.
Installing Xorg is simple as:
$ sudo apt install xorg
or for just the X11 server itself without drivers and utilities:
$ sudo apt install xserver-xorg-core
Note that with the latter you won't have the startx command (provided by bin:xinit but if you install it directly it'll pull all video drivers) and therefore will have troubles to start any graphical display.
If you wish to have a proper graphic session starter, you should consider running
$ sudo apt install xserver-xorg-video-xxx xserver-xorg-core xinit
where xxx is to be replaced by the name of your video driver.
To change system-wide keyboard settings run as root in a terminal:
# dpkg-reconfigure keyboard-configuration
Some settings are only accessible through editing xorg.conf by hand.
How can I edit my xorg config file?
Open a terminal (or console) as root, then run :
# editor /etc/X11/xorg.conf
What if I do not have a xorg config file?
If xorg.conf is missing for some reason, Xorg will probe your hardware on every startup. Though this works fine in most cases, some settings remain inaccessible. To create a starting point for customization, do the following.
Switch to a console as root (not a terminal emulator in X), then run:
# /etc/init.d/gdm stop || /etc/init.d/gdm3 stop || /etc/init.d/kdm stop || /etc/init.d/xdm stop || /etc/init.d/lightdm stop $ cd /etc/X11/ # Xorg -configure
Alternatively, reboot the machine in single user mode, then run:
$ cd /etc/X11/ # Xorg -configure
Follow the on-screen instructions. This should give you something to work with.
Question: what should be done if generating this file fails, giving the message, 'Number of created screens does not match the number of detected devices'?
Anyway, probably, this is unnecessary. Per this comment and this advice, it seems best to create the directory /etc/X11/xorg.conf.d and place in it a few files in order to tweak sections of the implicit xorg.conf, as for example is done here.
Xorg reads vendor configuration information from the directory /usr/share/X11/xorg.conf.d, as stated by man xorg.conf.d.
Rather than in xorg.conf, another quite useful way to adjust X settings is on the fly, in a desktop environment's list of scripts to run at startup.
After installation a user can create an X session with startx, a front end to xinit.
$ cat .xsessionrc xrandr --output DVI-I-1 --primary --mode 1600x900 --rate 59.98 --output VGA-1 --mode 1280x1024 --rate 75.02 --right-of DVI-I-1
# service gdm start
The display manager is available to multiple users.
See xserver-xorg-video packages.
- Q. How can I change the reference to a driver in my config file ??
- Solution: Edit xorg.conf and change the driver name in the "Device" Section (i.e. Driver "svga").
X.Org wiki contains useful information about X.Org. If you are having problems with X.Org, this is a good place to search for answers.