If you've ever been working on a WebObjects project and thought to yourself "I wonder if anyone has written this?" or "Gee, this seems like it could be easier", then Project WOnder is the thing for you. Project WOnder is a massive open-source Java project designed to ease the development of WebObjects applications. The project contains many subsystems - reusable components, frameworks, database plugins, many utilities, and a set of sample applications that show off some of Wonder's features.
The power, size, and scope of Project WOnder are both a blessing and a curse. To the initiated, the answer to most WO questions is "Project WOnder." However, many people seem to be turned off by the apparent complexity of using WOnder. With the deployment of the nightly build server, though, these fears are mostly unfounded. Installing and using Project WOnder requires adding a handful of Frameworks to your project and changing your Application, Session, and DirectAction superclasses to be ERXApplication, ERXSession, and ERXDirectAction, and you're done. WOnder will do the rest for you, bringing in patched, enhanced, and just-plain-better versions of various core WO components, and providing a huge number of prebuilt components and technologies to pull from to build your WO applications. It is WELL worth the time to start using it if you do anything beyond the simplest of applications.
For a slightly dated, yet still good, walkthrough you can check out Jonathan Rentzsch's 2002 CAWUG presentation.
The project itself is hosted at GitHub at https://github.com/wocommunity/wonder, and has a nightly build server at http://wocommunity.org/wonder/latest (the frameworks are in the file named Wonder-Frameworks.tar.gz).
The latest javadoc is available at http://wocommunity.org/documents/javadoc/wonder/latest .
Any questions can be directed to the mailing lists.
Wonder Community Tutorials available at: ObjectStyle Confluence Wiki WOnder Tutorials
Wonder's bug tracker is available at https://github.com/wocommunity/wonder/issues