O/R mapping tools

I have had some experience with some O/R mapping tools such as TopLink and Hibernate.
But I did not know that the market is flooded with a variety of OR tools.
Here are a few of them:

Abra - http://abra.sourceforge.net
BasicWebLib - http://basicportal.sourceforge.net/
Castor - http://castor.exolab.org
Cayenne - http://objectstyle.org/cayenne/
DataBind - http://databind.sourceforge.net
DB VisualArchitect - http://www.visual-paradigm.com/dbva.php
EnterpriseObjectsFramework - http://www.apple.com/webobjects/
Expresso - http://www.jcorporate.com
FireStorm - http://www.codefutures.com/products/firestorm
Hibernate - http://www.hibernate.org
Hydrate - http://hydrate.sourceforge.net
iBATIS DB Layer - http://www.ibatis.com
Infobjects ObjectDRIVER- http://www.infobjects.com
InterSystems Cache - http://www.intersystems.com
Jakarta ObjectRelationalBridge - http://db.apache.org/ojb
Java Ultra-Lite Persistence (JULP) - http://julp.sourceforge.net
Jaxor - http://jaxor.sourceforge.net
JdoGenie - http://www.jdogenie.com
JDOMax - http://www.jdomax.com
JDX - http://www.softwaretree.com
KodoJdo - http://www.solarmetric.com/Software/Kodo_JDO/
LiDO - http://www.libelis.com
O/R Broker - http://orbroker.sourceforge.net/
Persistence EdgeXtend - http://www.persistence.com/products/edgextend/
PlanetJ's WOW = http://planetjavainc.com/wow.html
PowerMapJdo - http://www.powermapjdo.com
Signsoft intelliBO - http://www.intellibo.com
SimpleOrm - http://www.SimpleOrm.org
SpadeSoft XJDO - http://www.spadesoft.com
Sql2java - http://sql2java.sf.net
Sun Microsystem certified (SunTone?) - FrontierSuite? for J2EE & J2SE - http://www.objectfrontier.com
Sun Microsystem certified (SunTone?) - FrontierSuite? for JDO - http://www.objectfrontier.com
The ProductivityEnvironmentForJava (PE:J) - http://www.hywy.com/
TopLink - http://otn.oracle.com/products/ias/toplink/content.html
VBSF - http://www.objectmatter.com


Also the following articles give some some good introduction to O-R mapping tools and their comparisions:
http://c2.com/cgi-bin/wiki?ObjectRelationalToolComparison

http://www.agiledata.org/essays/mappingObjects.html

http://madgeek.com/Articles/ORMapping/EN/mapping.htm