karabiner-remap-caps.xml

<?xml version="1.0"?>
<root>
  <item>
    <name>Remap Caps Lock to Command + Option</name>
    <appendix>Remap Caps Lock to Command + Option to allow you to cycle through tabs in many OS X applications using only one key instead of two.</appendix>
    <identifier>caps_lock_to_command_option</identifier>
    <autogen>
      __KeyToKey__
      KeyCode::F19,
      KeyCode::COMMAND_L,
      ModifierFlag::OPTION_L
    </autogen>
  </item>
</root>