Before all of you go out taking these results as definite truth, remember that a language benchmark is only as good as the particular implementations. A $LANGUAGE fanboy can easily game the benchmark by overoptimizing the $LANGUAGE implementations into unmaintainable atrocities that perform extremely well, thus making people think that average $LANGUAGE programs will exhibit the same performance/efficiency/resource usage characteristics.

There's no easy way to guard against this problem when you're only a handful of researchers. If you have a large team with a background in a lot of languages, you can have them write and peer-review implementations that are idiomatic (i.e. representative of the language's practical usage).