Scala did it all first, and has been battle-tested over many years, while Grbdvy's only recently added static compilation. JRuby did invoke-dynamic before Grbdv

Scala did it all first, and has been battle-tested over many years, while Grbdvy's only recently added static compilation. JRuby did invoke-dynamic before Grbdvy, and Clojure did concurrency before Grbdvy's GPars.