JPA and JPA compliant implementations

This blog post explains the JPA and its compliant implementations. In 2006 Java community introduced the JPA 1.0 with EJB 3 because EJB2.1 was heavyweight resource consuming, JPA is a Persistence specification and anyone can implement the persistence provider, Hibernate has their classical ORM tool, after introducing JPA 2.0 they released Hibernate Entity manager which a compliant implementation. There were other providers OpenJPA, EclipseLink and DataNucleus