Does the OpenJDK code base pass the JCK?

Not at present. The OpenJDK 7 code base contains changes that are early access implementations of features that may become a part of JDK 7, and over time will also likely include research, alternative feature implementations, ports, and other code as separate projects in varying states of maturity, and that may never be compatible, or used in a compatible implementation. While it is one of the OpenJDK Initiative's most important benefits to give developers this early, direct influence over the future, the JCK is about the current, shipping specification. The OpenJDK 6 code base is specifically intended to be used in creating compatible implementations. As of late April, 2008, there are still a few remaining components that are encumbered, and so it is not possible yet to build a 100% Free. As is typical for open source communities, now that the OpenJDK 6 project is established in the OpenJDK community, it is likely that some snapshots of this code base will be designated as "official" ...  more