Relax and don't be afraid (your language is safe) and always will be. The C version is not fully optimized (yes it's naive) and this was intentional and stated

Relax and don't be afraid (your language is safe) and always will be. The C version is not fully optimized (yes it's naive) and this was intentional and stated in the article (perhaps not clearly enough). A fully optimized C version would run in under 5 seconds for the 1000x1000 board on the same hardware using all the 'idiomatic' tricks using bit masks etc. A similarly optimized Lisp version would also run faster using different data structures and/or algorithms. You've missed the point. Learn to read logarithmic graphs without prejudice, you may discover much useful information around you that you assumed was 'useless'. Yes Lisp is an implementation of Lambda Calculus : horrific isn't it ? http://en.wikipedia.org/wiki/Lisp_(programming_language) http://en.wikipedia.org/wiki/Lisp_(programming_language) I don't know how many times I have to say this : Lisp is a functional language but also allows for imperative programming. You're only valid point was the misuse of "it's" instead of "its". Good job.