{ pkgs, ... }: {
  environment.systemPackages = with pkgs; [
    devilspie2
    find-cursor
    xed-editor
    sxhkd  # hotkeys
    peek  # simple video recorder
    birdtray  # thunderbird on the tray
    pdfpc  # PDF multi-monitor presenting
    glava  # video visualiser

    #== X11 tools ==#
    xev  # print events in terminal
    xhost  # manage host/user names, allowed xserver access
    xclip  # access X11 clipboard from command-line
    clipnotify  # notify on text selection events
    xdotool  # simulate keyboard & mouse activity
    xmodmap  # modify keymaps
    setxkbmap  # configure keymaps
    xcape  # configure modifier keys
    xfontsel  # browse and preview fonts
    xprop  # display and set window and font properties
    xwininfo  # print information about a window
    wmctrl  # manage windows

    #== Terminal emulators ==#
    terminator
    xterm

    #== Configuration ==#
    feh
    arandr
    pavucontrol
    piper

    #== Files and filesystems ==#
    gparted
    qdirstat
    timeshift
  ];

  services.ratbagd.enable = true;

  systemd.user.services = {
    devilspie2 = {
      description = "devilspie2 runner";
      wantedBy = [ "graphical-session.target" ];
      wants = [ "graphical-session.target" ];
      after = [ "graphical-session.target" ];
      serviceConfig = {
        ExecStart = "${pkgs.devilspie2}/bin/devilspie2";
        Restart = "on-failure";
        RestartSec = 1;
        TimeoutStopSec = 10;
      };
    };
  };

  services.xserver = {
    # xkbmap
    xkb.layout = "us,bg-custom";
    xkb.variant = ",phonetic-nonstandard";
    xkb.options = "grp:rwin_toggle,grp:alt_shift_toggle,lv3:switch,caps:escape";
    xkb.extraLayouts.bg-custom = {
      description = "Non-standard variant of the traditional Bulgarian phonetic keyboard, which replaces some characters with their English counterparts";
      languages   = [ "bg" ];
      symbolsFile = ../../packages/bg-custom;
    };
  };
}