At a previous JRubyConf, we talked about Thnad, a fictional programming language. Thnad served as a vehicle to explore the joy of building a compiler using JRuby, BiteScript, Parslet, and other tools. Now, Thnad is back with a second runtime: Rubinius. Come see the Rubinius environment through JRuby eyes. Together, we'll see how to grapple with multiple instruction sets and juggle contexts without going cross-eyed.