OpenSearch

Add OpenSearch discovery and querying to your WordPress site, based on the
OpenSearch specification, version 1.1.

After activating the plugin, your WordPress site will expose a standardised
search interface, accessible to OpenSearch clients such as the Firefox
search bar.

WordPress and WordPress MU:

1. Unpack the plugin into /wp-content/plugins/.
2. Activate the plugin through the ‘Plugins’ menu in WordPress.

WordPress MU for all users:

1. Unpack the plugin into /wp-content/mu-plugins/.
2. Make a symlink to opensearch.php in the mu-plugins directory.

1. 

   OpenSearch interface exposed in the Firefox search bar.