Both IBM (in J9) and BEA (in JRockit) own 100% of the JVM - the virtual machine - that is just part of the JRE (Java Runtime Environment). Both J9 and JRockit are clean-room implementations of the virtual machines - this is where the biggest "magic" is in terms of performance, manageability, stability, etc. You are right to point out that the class libraries come from Sun, and while both IBM and BEA modify some of these libraries, they are derivative works of Sun's IP, so they can't open source those.
Unless Sun follows the friendly gesture and donates the rights for those those pieces too ;-) Something that would, indeed, bring some harmony in the picture.
-- Stefano.
