Standard system Preferences allows you to change modifier keys to other modifier keys such as "command keys to control keys".

Karabiner has more flexible settings.
For example, the following setting changes the left command key to the control key.
You can use both command and control modifiers by thumb.

macOS provides Emacs key bindings (control-p, control-n, etc.) in text editing.
Karabiner enhances these Emacs key bindings and allows you to use them everywhere. (eg: operations in Finder)

Note:
These settings will be disabled in Emacs, Terminal or other apps that has native Emacs key bindings support.
You can use native functions in these apps even if you enabled these Emacs Mode settings.

Unintended Command-Q sometimes happens when you want to type Command-W because Command-W and Command-Q keys are too close.
This setting requires typing Command-Q twice in order to avoid unintended Command-Q.

You can use the hjkl keys as the arrow keys. (hjkl == left,down,up,right)
(The hjkl keys will be changed to the arrow keys while you are pressing S key.)

This settings allows you to use arrow keys with keeping your fingers on the home row of keyboard.

Use IJKL keys

Please use this private.xml if you want to use IJKL keys.

(private.xml usage)

You can control pointer cursor and scroll wheel from keyboard.

Use IJKL keys

Please use this private.xml if you want to use IJKL keys.

(private.xml usage)

This setting allows you to operate Finder by hjkl keys.
Unlike other Vi Mode, you don't need to press modifier keys.

Use IJKL keys

Please use this private.xml if you want to use IJKL keys.

(private.xml usage)

You can switch apps directly by Launcher Mode v2.
It's more efficient than command-tab. You don't have to choose apps from list.

For example:
If you want to open Mail, type M key while pressing O key.
If you want to open Safari, type S key while pressing O key.
Thus, you can open apps by type key while pressing O key.

And you can modify Launcher Mode v2 by private.xml.
For example, this private.xml adds following shortcuts.

  • Open Maps by C key while pressing O key.
  • Open FaceTime by V key while pressing O key.
<?xml version="1.0"?>
<root>

  <vkopenurldef>
    <name>KeyCode::VK_OPEN_URL_APP_Maps</name>
    <url type="file">/Applications/Maps.app</url>
  </vkopenurldef>

  <vkopenurldef>
    <name>KeyCode::VK_OPEN_URL_APP_FaceTime</name>
    <url type="file">/Applications/FaceTime.app</url>
  </vkopenurldef>

  <replacementdef>
    <replacementname>LAUNCHER_MODE_V2_EXTRA</replacementname>
    <replacementvalue>
      <![CDATA[
        <autogen>
          __KeyDownUpToKey__
          KeyCode::C,
          KeyCode::VK_OPEN_URL_APP_Maps,
        </autogen>

        <autogen>
          __KeyDownUpToKey__
          KeyCode::V,
          KeyCode::VK_OPEN_URL_APP_FaceTime,
        </autogen>
      ]]>
    </replacementvalue>
  </replacementdef>

</root>

This setting is useful if you are using a compact keyboard with MacBook family and place it on the built-in keyboard.

This setting suppresses duplicated events if your keyboard or mice send same events multiple times when you press key once.

You can adjust threshold in Parameters tab.