JEP253 aims to prepare JavaFX for Project Jigsaw by defining public APIs for functionality that will become inaccessible due to modularization.
The JDeps Maven Plugin will break a project’s build if it contains dependencies on JDK-internal APIs. This helps to prepare for Java 9, where these dependencies will be unaccessible.
With Java 9 comes Project Jigsaw – a modularization of the JDK – which will break existing code. An overview over the planned changes lets you see whether yours is affected.