JDK 5.0 Source Code & Licensing Overview
Binary Code
The JDK and JRE are the two software deliverables of J2SE. The binary form of the JDK and JRE are licensed under Sun's Binary Code License (BCL) with Supplemental Terms.
For most developers and end-users, the binary JDK and binary JRE are all that's needed to experience the world of Java technology. (Of course for developers, an Integrated Development Environment (IDE) such as NetBeans is also recommended and is a handy compliment to the JDK).
The binary JDK and JRE are available at no-fee from Sun (per terms of the BCL) for use with desktop personal computers. Both the JDK and JRE can be freely redistributed with value-add. JDK or JRE use for embedded devices and other computing environments may require a license fee from Sun.
Download the binary JDK, JRE, or NetBeans co-bundle.
Source Code
Sun also makes the JDK source code available for researchers and others interested in exploring the details of the JDK. Over the past several years, Sun has made the source code available via the Sun Community Source License (SCSL) terms. Sun continues to use SCSL for JDK 5.0. In addition, Sun is also releasing JDK 5.0 under the new Java Research License (JRL) which simplifies access to JDK 5.0 source code. Researchers and universities should find the JRL much easier to understand and work with compared to SCSL.
Note that in either case (SCSL or JRL), if you decide to use your project internally for productive use or distribute your product to others, you must sign a commercial agreement and meet the Java compatibility requirements.
Download JDK 5.0 source via JRL
J2SE Documentation
Generally, the J2SE documentation is not redistributable. Individuals can download the J2SE documentation for their own use or simply browse online.