The document discusses Java updates in JDK 9, with highlights including:
- Modularity improvements like modular source code and modular run-time images.
- Developer convenience features such as simplified Doclet API and Java shell.
- Diagnostic updates like standardized GC logging and additional diagnostic commands.
- Removal of some deprecated JVM options and garbage collector combinations.
- Updates to strings, Javadoc, JavaScript/HTTP support, and various native platform improvements.