That's like asking what does a program do and being told, "it does what the code says." Technically true, but not what we mean when we ask. Also, I don't think that's really what the site's authors thought. After all, when I click on the Haskell page, I don't see a comparison of Haskell programs, but a comparison of the fastest Haskell program with the fastest Java program. It's not obvious to me what that means, or even that it means anything at all.
> Seems like your idea of a comparison, between for-example Lisp and Java programs, would require writing all the Lisp programs as if they were being written in Java. (We used up our "one variable change" with SBCL instead-of OpenJDK).
That's exactly right, but because that's rather tedious, I would present just meaningful comparisons rather than non-meaningful ones, so no inter-language comparisons. I'm not saying they're always meaningless, but they can't be made with the data currently available on that site. Unfortunately, we cannot manufacture (non-fictitious) meaning out of data as we like.
> Do you mean that you made mistakes when you made your summary.
Yes. By "better than nothing" I overestimated the significance of results, at least in this case. After a closer look I realized that different programs use different algorithms, and so the comparison tells me nothing about the relative speed of those languages.