Has a history, but widely adopted only since open-
source Hibernate project started, 2001-2002.
The Hibernate project  was founded and led by
Gavin King, a Java/J2EE software developer, now
part of Jboss. King wrote an excellent book .
Microsoft has adopted a comparable approach with
EDM, Entity Data Model and its Entity Framework,
for release this year. [1, 10]
Both Hibernate and EDM support (or will support)
multiple databases: Oracle, DB2, SQL Server, …