[Pharo-dev] Pharo and Amber relationship

Hi, as I read somewhere that Amber want to stay compatible with Pharo (at least with the core classes) I wonder how this compatibility is measured/enforced these days. Are there tools to exchange code between the two? I also wonder if what would be necessary to run Amber on Java Nashorn (a JS engine that comes with the JDK 8). Could serve as a horse to also run on JVM... Why I'm asking: I think one of our goals should be to make Pharo more widely usable to not end up as an island. If Pharo and Amber stay compatible to a certain amount Amber could open the door for Pharo to other target platforms (browser, mobile devices, other language runtimes) as JS is available nearly everywhere. Thx T.