The source for LL is available at http://github.com/kstephens/ll/tree/master.
Also located there are the slides from my June 2008 talk at the Chicago Lisp Users Group on the design of the LL object-oriented Scheme interpreter:
http://github.com/kstephens/ll/tree/master%2Fsrc%2Fll%2Fdoc%2Fll_system_…