My understanding is that the original incarnation of JDO required the use of XML files to describe the metadata but I see that the most recent version allows annotations.
Is this correct?
If so, when did annotations first become available in JDO as an alternative to XML?
From apaches JDO page:
The JDO 2.1 maintenance release provides support for JDK 1.5 features,including the use of annotations as a means of specifying mapping.
Most recent release is JDO 2.2, for 2.3 there's an early access release (again, this information is valid for apache JDO).