>> Another question is whether there should exist a "sys lisp" that can form the lisp core of higher level lisps but that itself is not a garbage collected lisp

>> Another question is whether there should exist a "sys lisp" that can form the lisp core of higher level lisps but that itself is not a garbage collected lisp... You may be interested in Henry Baker has a paper where he shows a VM where the semantics prevent garbage from being created http://home.pipeline.com/~hbaker1/LinearLisp.html http://home.pipeline.com/~hbaker1/LinearLisp.html