Sun Microsystems Inc’s new Java license model does not require licensees to return IP to Sun, except where their technology is used to extend the Java platform or in APIs extensions created by the so-called expert groups. Pricewaterhouse Coopers is overseeing the whole process to ensure fair play. Sun’s document says: For extensions, the community member making the extension is required to supply specifications and, ultimately, test suites. Moreover in some cases neither a test suite nor a good specification may not be enough to guarantee that a modification, extension, or bug fix is compatible. For some purposes a reference implementation can provide not only a base on which to build a commercial version of a specified piece of functionality but a guide to ensure correctness.