What is Doctrine? Doctrine is a popular ORM for PHP which works with RDBMS via PHP objects. This is built inspired by Hibernate from JAVA. This acts as an abstraction layer between PHP and RDBMS. What is it good for? It really hide the the business logics (tables, sql, relations) via the db abstraction layer while active record map objects to tables. It has a strong caching (of cached caching) system with apc, memcached, sqlite Caching...