Tamarin
Frank Hecker: Adobe has now taken the code for that AVM2 virtual machine implementation and released it as open source through the Mozilla project as Tamarin.
If we take as a given that this runtime will be ubiquitous, debugged, and performant; and couple this with the recent trends to retarget popular languages to run on a common VM, then why not port some of these same languages to a runtime which actually was designed for a dynamic language?