Use this tag for questions specific to Java 9, which is version 9 of the Java platform, released on the 21st of September 2017. In most cases you should also specify the java tag.
Oracle has released its updated list of proposed or targeted Java 9 enhancements. In addition to previously confirmed Java modularity updates, the most recent list includes a common logging system for all JVM components (JEP 158), more HotSpot JIT compiler controls (JEP 158), and refinements to improve the efficiency of garbage collection (JEP 214), and repair issues introduced by Project Coin language updates in JDK 7 (JEP 213). This is also the first release under the new version-string schema (JEP 223) and will hence be officially be numbered 9, not "1.9.0" as was the case for earlier versions.
Even with delays, Oracle has been steadily moving forward with its plans to modularize the JDK. But the scope of Java modularity took a step up in September, when Oracle announced four new JEPs, including JEP 220: Modular Run-Time Images. Ben Evans, writing for InfoQ, noted that swapping JARs for modules is the "point of no return for modularity," with serious implications for IDEs, toolmakers, and many Java application frameworks:
After this point, The Java Runtime Environment (JRE) will no longer be contained in jar files, and instead will be composed of modules (JSR 376). Files such as rt.jar and tools.jar no longer exist in the JRE. The platform will continue to accept and run applications and libraries packaged in conventional jar files, modular jar files, or in the new module file format. The intention is that over time, application developers wil migrate to the new modular formats as well.
See "Oracle Commit to Java Modularity" for more from Ben Evans on modularity updates in Java 9. Also see Takipi Blog: "Java 9 – The Ultimate Feature List" for a comprehensive (as of November 20, 2014) description of new features accepted or proposed for the next major release of Java, and "What's New in Java 9? (Besides Modules)" for another more recent compilation of features.
The API documentation of the release can be accessed at Oracle's technetwork.
