Actually large parts are under the Universal Permissive License these days, which explicitly deals with patent grants. e.g. https://github.com/graalvm/graaljs

Actually large parts are under the Universal Permissive License these days, which explicitly deals with patent grants. e.g. https://github.com/graalvm/graaljs/blob/master/LICENSE https://github.com/graalvm/graaljs/blob/master/LICENSE https://opensource.org/licenses/UPL https://opensource.org/licenses/UPL I think Graal itself is GPL2+Classpath because it's derived from a codebase that was itself licensed that way, not because Oracle actually want ambiguity. If they wanted that, their new from-fresh codebases wouldn't be under a more precise open source license.