"Interlisp is a very large software system"

"Interlisp is a very large software system and large software systems are not easy to construct. Interlisp-D has on the order of 17,000 lines of Lisp code, 6,000 lines of Bcpl, and 4,000 lines of microcode."

http://www.softwarepreservation.net/projects/LISP/interlisp-d/Papers_On_Interlisp-D.pdf

This statement amused me. 1980 really was a different world.

In comparison, SBCL has 555K lines of lisp code.