What are TCKs? What is the JCK?
Technology Compatibility Kit (TCK) is a conformance test suite that is used to verify that an implementation of a Java technology conforms to its specification. If an implementation passes all of the tests in the TCK and meets all of the additional Compatibility Requirements defined by that TCK then it is Compatible. The Java Compatibility Kit (JCK) is the TCK for the Java SE Platform; an implementation of Java SE must pass all of the tests in this TCK and meet all of its compatibility requirements in order to be Compatible. (There are also additional TCKs for technologies that can be incorporated into the Java SE platform for example, the BeanInfo, SmartCardIO, JAXB, JAXP, and JAX-WS TCKs).