Second, to make the comparison as unbiased as possible, we coded the same algorithm in each language without adapting it to the peculiarities of each language (which could reflect more about our knowledge of each language than of its objective virtues).
They have invited others to fork the code on github and write the fastest possible for each language.
To make the comparison "as unbiased as possible" would be to code the same algorithm but adapt it to the peculiarities of each language implementation.
I will be interested to see whether people can whittle down the respective benchmarks.
They wrote the code for each language based on prior knowledge about each language, and/or from likely googling how-to's... far from performant code with any language.
A mild understanding of each language could yield dramatic performance improvements over not understanding it at all.