Why is (some) free software not implementing Java2?
Sun has made public statements in connection with their legal strategy in the Sun-Microsoft lawsuit that indicate that the company considers the published specifications of Java2 to be intellectual property that can not legally be used by persons involved in efforts to create Java2 clean-room implementations. For this reason, some open source projects have decided to not implement Java2 any time soon. One example is Kaffe. Some projects (like the Classpath project) have decided to challenge Sun’s legal position and are going ahead with Java2.