Sun also distributes a superset of the JRE called the Java 2 SDK
(more commonly known as the JDK), which includes development tools such as the Java compiler, Javadoc, and debugger.
With the release of Java 2 SDK
1.4, Swing's performance is even better.
Meantime, Sun is now shipping the Java 2 SDK
- actually version 1.2.1 - for Solaris with its new Java virtual machine, which it claims offers 500% better performance than the current version.
The current version of the Java 2 SDK
is 1.4, but Sun updates Java 2 frequently; don't be surprised if you find versions 1.5 or beyond on Sun's Web site.