@Dennis The only thing is the source of the interpreter is
github.com/rakudo/rakudo or
rakudo.org .
github.com/nxadm/rakudo-pkg is only about packaging it up for distribution. Rakudo is just an implementation of the spec
github.com/perl6/roast (granted it is the only one currently). It is the MoarVM version (instead of JVM or Javascript) which is at
github.com/MoarVM/MoarVM and it there is NQP between the two
github.com/perl6/nqp.