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?

Would SectorLISP (https://justine.lol/sectorlisp2/) count? It can run the LISP 1.5 metacircular evaluator.

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]

[1] https://paulgraham.com/rootsoflisp.html

Check Zenlisp and Kilo Lisp under http://t3x.org

Not the smallest, but a great example on how a Lisp can be reimplemented.

Also, http://www.t3x.org/lisp64k/index.html

Boot sector lisp?

https://github.com/jart/sectorlisp