Lisp is Slow (NOT!) summarizes a comp.lang.lisp thread in which some knucklehead said “lisp is slow”, and furthermore that
The best known non-stupid (real problem, any algorithm) benchmark is probably the Coyote Gulch test. There are many languages that it has been translated into. If you can produce (write or find) and post a Lisp version that is within 10% of C performance, I will admit that #1 [lisp is slow] is incorrect.
Within a few days a collaborative programming and optimization effort paid off with a lisp version of the benchmark that was about 2% faster than the C version.