PUC Lua is about 20k lines of ANSI C code. The "ANSI" part makes it a bit old-fashioned sometimes but it is very readable. Maybe you were thinking about the Lu

PUC Lua is about 20k lines of ANSI C code. The "ANSI" part makes it a bit old-fashioned sometimes but it is very readable. Maybe you were thinking about the LuaJIT code base? That one is indeed very tricky, in part because a lot of it is in ASM and in part because the algorithms behind it are very tricky. I doubt anybody other than Mike Pall understands it all.