Slightly unrelated, but you take what (hn item) you can get: What is the smallest lisp (semantically/language-wise) people know, that could be used for implementing itself? Theoretical or practical/"real" is less relevant, mostly just curious. So far, it seems Bel (by pg) might get the closest, but can't claim to be an expert, surely could be something smaller out there?
This is pretty small.
http://scheme.dk/blog/2006/12/self-evaluating-evaluator.html
Is Bel a smaller LISP than what's described in The Roots of Lisp? [1]
Check Zenlisp and Kilo Lisp under http://t3x.org
Not the smallest, but a great example on how a Lisp can be reimplemented.
Boot sector lisp?
Would SectorLISP (https://justine.lol/sectorlisp2/) count? It can run the LISP 1.5 metacircular evaluator.