The possible new database layer for WordPress core
The mysql_* functions are officially deprecated for PHP 5.5 and are throwing E_DEPRECATED errors. On http://core.trac.wordpress.org/ticket/21663 there is discussion on this topic.
This plugin reflects those discussions.
Why should I use this plugin?
You should use this plugin if you want to help test the proposed changes for PDO / MySQLi for WordPress. Or if you need PDO / MySQLi support for some reason (e.g. you're running php 5.5, your server doesn't have classic mysql bindings, etc.)
This plugin is still in development.