Q. How can we make an AI that replicates and enhances itself?
A. Certainly with the ghost.pl AI in Perl, and possibly also with MindForth, especially in Perl it is easy to write code that will read in its own program as a mind1.pl file, insert any new words or new ideas into the MindBoot sequence, write the expanded AI as a mind2.pl file, schedule the mind1.pl to die soon, and start the mind2.pl running as an enhanced AI ready to replicate itself and enhance itself even more.
http://groups.google.com/d/msg/comp.lang.perl.misc/Ep8XTYKU6Jw/0OWMiO1gBgAJ