In eclipse, the "default implementation library" what jars files do I need to include if I do not want to use server runtime?
I'm refering to this tutorial http://help.eclipse.org/help33/index.jsp?topic=/org.eclipse.jpt.doc.user/task_create_new_project.htm
Depends on what implementation you want to use. There are currently three most popular implementations: Hibernate, TopLink and EclipseLink.
I know about hibernate that it's README file explains what jars are mandatory for what functions. If you use JPA you must have some sort of EntityManager (hibernate can be used without EntityManager too), so you need all the dependencies of it.
To download hibernate JPA implementation use this link. You need hibernate core, annotations and entity manager for JPA. If you use all the jars in those three packages you should be ok. But I strongly suggest you to read the README files.
Follow Using TopLink JPA with Dali to get started with the Toplink Essentials (JPA reference implementation). To get the mentioned jars (toplink-essentials.jar and toplink-essentials-agent.jar), download them from there or, if you use Maven, from the Java.Net Maven Repository.
PS: Please note that after 2.0-b36, the toplink-essentials-agent.jar file is no longer needed as the agent facility is now integrated into toplink-essentials.jar. So you can do like below.
$ java -javaagent:toplink-essentials.jar client.Client