MongoLantern WP is a wordpress plugin to enable MongoLantern Fulltext Search Engine into WordPress.
Here is the getting started guided to get going with MongoLantern WordPress plugin. Getting Started with MongoLantern WP
To use MongoLantern: * you must install mongodb server(http://www.mongodb.org/downloads). * you must also install mongo-php extension(http://www.mongodb.org/display/DOCS/PHP+Language+Center) to the web server or into your CGI process.
Yes, surely. MongoLantern is designed to be compatible with any wordpress template having search facily embeded into.
If the search box is not embeded into theme itself then you can use the WordPress Sidebar Search widget, to use MongoLantern.