Nice. The first Lisp interpreter whose source code I was able to dissect (as a student, source code generously provided by my professor), was the Lispf3 interpreter written in (gasp ;-) Fortran.
Sidenote: the garbage collector was in file garb.f (IIRC) and I lost this file soon when I did a "rm garb" to clean up my account on the BSD VAX where I kept it. But still have the line printer output :-)
Awesome, thanks for the link. I'll probably use that as a response whenever someone complains about compilation/setup being too complicated - the compilation instructions on page 4 should give them a proper baseline ;)
[0] https://en.m.wikibooks.org/wiki/Write_Yourself_a_Scheme_in_4...