Every JDK I'm aware of contains the following text in its license. It specifically grants a license to the specification (API) for the purposes of creating a cl

Every JDK I'm aware of contains the following text in its license. It specifically grants a license to the specification (API) for the purposes of creating a clean room implementation. There is only ONE possible expression of the specification, in Java. "Sun hereby grants you a fully-paid, non-exclusive, non-transferable, worldwide, limited license (without the right to sublicense), under Sun's intellectual property rights that are essential to practice the Specification, to internally practice the Specification for the purpose of designing and developing your Java applets and applications intended to run on the Java platform or creating a clean room implementation of the Specification that: (i) includes a complete implementation of the current version of the Specification, without subsetting or supersetting; (ii) implements all of the interfaces and functionality of the Specification without subsetting or supersetting; (iii) includes a complete implementation of any optional components (as defined by the Specification) which you choose to implement, without subsetting or supersetting; (iv) implements all of the interfaces and functionality of such optional components, without subsetting or supersetting; (v) does not add any additional packages, classes or interfaces to the "java." or "javax." packages or subpackages or other packages defined by the Specification; (vi) satisfies all testing requirements available from Sun relating to the most recently published version of the Specification six (6) months prior to any release of the clean room implementation or upgrade thereto; (vii) does not derive from any Sun source code or binary code materials; and (viii) does not include any Sun source code or binary code materials without an appropriate and separate license from Sun. The Specification contains the proprietary information of Sun and may only be used in accordance with the license terms set forth herein. This license will terminate immediately without notice from Sun if you fail to comply with any provision of this license. Upon termination or expiration of this license, you must cease use of or destroy the Specification."