Hibernate is a powerful, ultra-high performance
object/relational persistence and query service
for Java. Hibernate lets you develop persistent
objects following common Java idiom - including
association, inheritance, polymorphism, composition
and the Java collections framework. Extremely
fine-grained, richly typed object models are
possible. The Hibernate Query Language, designed
as a "minimal" object-oriented extension to SQL,
provides an elegant bridge between the object and
relational worlds. Hibernate is now the most
popular ORM solution for Java.