Java Pro - JDOQL: The JDO Query Language
- By David Jordan. Java developers currently have several data persistence techniques in their repertoire. However, each of these techniques has its drawbacks. See how JDO and its query language JDOQL avoid these shortcomings.
- http://www.fawcette.com/javapro/2002_07/magazine/features/djordan/

TheServerSide.com: Simplifying Domain Model Persistence in a J2EE application by using JDO
- By Chris Richardson. Learn how to use Java Data Objects (JDO) to accelerate development and test domain model outside of the application server and without a database.
- http://www.theserverside.com/tt/articles/article.tss?l=JDODomainModel

Signsoft intelliBO
- An implementation of the Java Data Objects standard (JDO). Includes many additional features and development tools. [Commercial]
- http://www.signsoft.de/signsoft/en/intelliBO/

BEA Kodo
- Implements the official Sun Java Data Objects Specification 1.0, providing transparent persistence for Java objects to a relational database. By BEA Systems, Inc. [Commercial]
- http://www.bea.com/framework.jsp?CNT=index.htm&FP=/content/products/weblogic/kodo/

Java Data Objects (JDO)
- A home page for JSR-000012, Java Data Objects.
- http://java.sun.com/products/jdo/

Castor
- Integrates Java objects, XML documents, SQL relational databases and LDAP directories in a unified model that allows information to be exchanged, persisted and manipulated in a variety of ways. Supports JDO. [Open Source, BSD-like]
- http://www.castor.org/

Java Persistent Objects (JPOX)
- JDO implementation using JDBC. A fork of TJDO with application identity, support for existing schemas, and conformance for J2EE. [Open source, Apache 2 license]
- http://www.jpox.org/

ONJava.com: Flawed JDO Points the Way to the "Objectbase" [Apr. 24, 2002]
- Java Data Objects (JDO) is neither a silver bullet nor without merit. But its most important contribution may be to wake developers up to the coming paradigm shift: from database to objectbase, a place where not only data but data and behaviors are stored
- http://www.onjava.com/pub/a/onjava/2002/04/10/jdbc.html

ONJava.com: Flawed Understanding of JDO Leads to FUD
- In this scathing response to Don Bales' recent critique of Java Data Objects, David Jordan offers proof that JDO does not regard SQL as a bad thing, yields shorter and simpler code, and is vendor-neutral.
- http://www.onjava.com/pub/a/onjava/2002/05/29/jdo.html

Persist data with Java Data Objects, Part 1
- Jacek Kruszelnicki discusses the issues encountered with persistence, presents traits for an ideal persistence layer, and reviews available JDO solutions.
- http://www.javaworld.com/javaworld/jw-03-2002/jw-0301-jdo.html

Persist data with Java Data Objects, Part 2
- This article presents two major JDO specifications: the Sun Microsystems JDO and the open source Castor JDO. Jacek Kruszelnicki discusses their relative pros and cons, and their similarities and differences.
- http://www.javaworld.com/javaworld/jw-04-2002/jw-0412-jdo.html

XORM (Extensible Object-Relational Mapping for Java)
- Provides interface-based persistence to RDBMSs while allowing developers to focus on the object model, not the physical layer. It implements many of the interfaces specified by JDO. [Open source, GPL]
- http://xorm.sourceforge.net/

ONJava.com: Using Castor JDO for SQL Mapping
- An in-depth look at using Castor's marshalling engine to do data binding of Java objects to tables, rows, and columns in an SQL database.
- http://www.onjava.com/pub/a/onjava/2002/10/02/jdosql.html

ONJava.com: "Castor JDO": Simply False Advertising
- This expert perspective lays it on the line: Exolab's Castor JDO product does not support the JDO standard.
- http://www.onjava.com/pub/a/onjava/2002/12/04/realjdo.html

TriActive JDO (TJDO)
- Implementation of Sun's JDO specification (JSR 12), designed to support transparent persistence using any JDBC-compliant database. [Open source, Apache Software License]
- http://tjdo.sourceforge.net/

Java Data Objects (JDO) by Gopalan Suresh Raj
- Starting with an introduction to JDO, it provides detailed code samples of developing applications with JDO. Articles and tutorials related to JDO.
- http://my.execpc.com/~gopalan/java/jdo/jdo.html

Java(TM) Data Objects (JDO) Specification
- The Proposed Final Draft of the JDO 1.1 specification for object-relational mapping on the Java platform.
- http://jcp.org/aboutJava/communityprocess/first/jsr012/index.html