Mapping Definitions in JPA and Hibernate : Annotations, XML or Both?

I am using Linux Ubuntu os, i want hibarnate external jar files for eclipse please help me where can I get Hibernate external jar files

I use XML mapping to have my data classes free of any hibernate imports, because I send them over socket to clients who don't have hibernate.

If orm.xml had the same amount of documentation/blogs/books/videos/stackoverflow community that annotations have, I would more than gladly use it!