Release 6.0.0 (aka "The Cleanup Release") have been released in the master branch of Project Wonder! Johann Werner wrote a nice change log on GitHub:
In short, we moved obsolete frameworks and examples to a Archives directory, JasperReport has been updated to v4.7 and all references to WO 5.3.3 have been removed.
The previous release of Wonder 5.x is available in the "wonder_5" branch. This branch won't have any commit activity in it, unless we need to commit a fix for a major bug (or if people are willing to submit pull requests to maintain it).
Many thanks to everyone who contributed to this release!