Language constructs

Autoboxing, enhanced loop construct, generics, metadata,

type safe enums, static imports, variable-length arguments

Virtual machine

Self-tuning heap, class data sharing, garbage collector

ergonomics, fatal-error handling

Core libraries

Networking, security, internationalization, printf-style

formatting, Java API for XML, collection framework support

for new constructs, bit manipulation, instrumentation

User interface

Internationalization, Java Sound, AWT, Swing, 2D graphics

improvements

Deployment

New hypercompression format for JAR files, improved

Java Web Start

Tools

Java Virtual Machine Tool Interface (JVMTI), Java Platform

Debugger Architecture (JPDA), improved compiler/javadoc