Ah yes, I saw the adjacent impls, didn't check deeper to see Epsilon was exactly what I was looking for. Thanks. I see even the ifaces are GPL sadly as are the impls. I am not sure the classpath exception applies to the interfaces. And I fear even reading/learning from the impls lest I want to use my GPL-gained knowledge on a distributed, non-GPL project.
GPL doesn't affect knowledge, only code. You can go work on proprietary software using things you learned by reading GPLd code, don't worry about that.
