Java Development Kit 7 (JDK 7) is the next major release of the Java SE platform. Through the OpenJDK project, JDK 7 has been a highly collaborative effort between Sun and volunteers from the Java developer community.
JDK 7 introduces several key features to improve performance, usability, and security of the Java platform. A detailed list of these features appears on the OpenJDK site.
Based on the feedback from the developer community and Sun's customers, the JDK 7 features primarily focus on the following areas:
-Modularization: A large-scale effort to refactor, or break up, the Java SE platform into smaller, separate, interdependent modules. Individual modules can then be downloaded as required by the Java virtual machine and/or Java applications. This effectively shrinks the size of the runtime on the user's machine.
One benefit of modularization is that the platform is a smaller download, potentially improving start-up performance. Having a smaller memory footprint also enables significant performance improvements, especially for desktop applications. A smaller platform also means it can now fit on devices with less memory.
You can find more information about modularization on the OpenJDK site, on Mark Reinhold's blog , or on the Project Jigsaw site.