Dalvik was licensed under the ASL on the premise that it was reverse engineered:
Licensing and patents Main article: Oracle v. Google
Dalvik is published under the terms of the Apache License 2.0. Google says that Dalvik is a clean-room implementation rather than a development on top of a standard Java runtime, which would mean it does not inherit copyright-based license restrictions from either the standard-edition or open-source-edition Java runtimes. Oracle and some reviewers dispute this.
What is, or will be, the license for ART (Android Runtime)?
I believe this is what a previous question was intending to ask, but the question wasn't exactly clear enough, perhaps. I hesitate to edit that question at this point.