Hibernate is a powerful, high performance object/relational persistence and query service. Hibernate lets you develop persistent classes following object-oriented idiom - including association, inheritance, polymorphism, composition, and collections. Hibernate allows you to express queries in its own portable SQL extension (HQL), as well as in native SQL, or with an object-oriented Criteria and Example API.
Unlike many other persistence solutions, Hibernate does not hide the power of SQL from you and guarantees that your investment in relational technology and knowledge is as valid as always. The LGPL open source license allows the use of Hibernate and NHibernate in open source and commercial projects.
Hibernate is a Professional Open Source project and a critical component of the JBoss Enterprise Middleware System (JEMS) suite of products. JBoss, a division of Red Hat, offers a range of 24x7 Professional Support, Consulting, and Training services to assist you with Hibernate.