The document discusses Java Development Kit (JDK) versions 10 and OpenJDK. It provides an overview of JDK 10 including new features like local variable type inference and consolidating the JDK source code into a single repository. It also discusses migrating to JDK 10 and modular development. Finally, it covers OpenJDK, the open source version of Java, including its release cycle and Oracle's OpenJDK builds.