CDD is included in the combined code and parser generator Laja.
Just download it and follow the installation instructions.
Download Laja2-007-beta or later (click the green download button to get the latest version) to get a version with support for CDD 2.0.
The file cdd-002-beta.jar (needs to be added to your Java/JVM project) can be downloaded from here.
Some functionality is missing in the first alpha release and is described here.
All code is hosted at GitHub and can be downloaded in
one zip file (2.8 MB).