Starting with MySQL 5.4.2, you do not need to do anything special to get or install the InnoDB storage engine. From that version forward, the plugin is the default way the InnoDB storage engine is packaged. Earlier versions of MySQL and the InnoDB storage engine required some extra build and configuration steps.
Report any bugs in the InnoDB storage engine using the MySQL bug database. For general discussions about InnoDB Storage Engine for MySQL, see http://forums.innodb.com.
This is the User’s Guide for InnoDB storage engine 1.1 for MySQL 5.5, generated on 2010-04-13 (revision: 19994) .