• ArchWiki: libinput
• Stack Exchange: Difference between .xinitrc, .xsession and .xsessionrc

• X server resource database utility: xrdb
• list all input devices: xinput list
• list properties of an input device: xinput –list-props 16
• show X events (for example to see keycodes): xev

• /usr/share/X11/xorg.conf.d: server configuration
• ~/.xinitrc: environment from xinit (startx)
• ~/.xprofile: environment of display manager, for example XFCE
• ~/.xsessionrc: executed on MX/Debian/Ubuntu GUI login

ln -s .xinitrc .xsessionrc

• reddit: Mouse speed in XFCE (libinput)
• StackExchange: How to change mouse speed/sensitivity?
• Patrick Mylund Nielsen: Lowering Mouse Sensitivity in Ubuntu and Fedora
• Nitesh Kumar: How to Change Mouse and Touchpad Settings Using Xinput in Linux

X server configuration in /usr/share/X11/xorg.conf.d/20-rat7.conf

# Edited by Ralf Hoppe <ralf@dfcgen.de>
# originally from https://community.linuxmint.com/hardware/view/10217
Section "InputClass"
Identifier "R.A.T."
MatchProduct "R.A.T.7"
MatchDevicePath "/dev/input/event*"
#
# https://delightlylinux.wordpress.com/2012/03/07/using-the-cyborg-r-a-t-7-with-ubuntu/
# https://askubuntu.com/questions/331508/buttonmapping-positional-parameters
# ftp://ftp.x.org/pub/current/doc/mouse.txt
Option "Buttons" "17"
# 1  left button
# 2  middle button
# 3  right button
# 4,5 neg/pos wheel
# 6,7 is the left/right wheel (see "ZAxisMapping")
# 8,9 thumb rest buttons
# 12 precision aim button
# 17 DPI settings button
Option "ButtonMapping" "1 2 3 4 5 0 0 8 9 7 6 12 0 0 0 16 17"
#         Option "ButtonMapping" "1 2 3 4 5 6 7 2 9 10 11 12 0 0 0"
Option "AutoReleaseButtons" "13 14 15"
# 4,5 is the typ. scroll wheel
# 6,7 is the left/right wheel
Option "ZAxisMapping" "4 5 6 7"
Option "AccelSpeed" "-0.6"
EndSection

• screen control and info: xrandr
• screen adjustment: xvidtune

• interactive key assignments (in ~/.Xmodmap): xkeycaps
• assign keycodes to keysyms: xmodmap -e “keycode 86 = KP_Add”

• show matching fonts: xlsfonts '*helvetica*'
• interactive font selection: xfontsel