Decker is one of the most insane codebases I've ever seen. It's almost entirely in one file in a very dense format:
https://raw.githubusercontent.com/JohnEarnest/Decker/refs/he...
I've read and written a lot of C over the decades but this borders on being an IOCCC entry...
On the other hand, while I completely agree about the C codebase, the Javascript is at least comprehensible. I've toyed around with adding a feature or two, and almost got there.
Looks like "Whitney C" https://www.aplwiki.com/wiki/Whitney_C
Not even remotely. it's just plain vanilla C, with dense formatting. Whitney makes extensive use of macros to completely change the language.