速度

Erlangの資料に、こんなことが書いてありました。
'Erlang - A survey of the language and its industrial applications' http://www.erlang.org/doc.html

7.2 Preformance
Erlang is sufficiently fast for delivering real telecommunication products.
Interestingly Erlang rarely does well in small benchmark comparisons with C. C programs are usually faster than the equivalent Erlang programs.
However, when talking about large systems the opposite seems to be true - usually the Erlang programs are faster than the C. The reasons for this are not well understood.

このころは、JAMという遅い処理系が主流だったころです。
"The reasons for this are not well understood."というところが可笑しいです。