If you compile the Rust example with optimization (-O) it just throws the result away, which gives the ~0.030 time chrisdouay found.

However, if you add a println!() around it, it has to calculate the result. Here's the running time:

    > time ./fib
    1134903170

    real    0m2.242s
    user    0m2.240s
    sys     0m0.000s

I tried the C example as well (with -O2) and found this:

    > time ./cfib
    1134903170

    real    0m4.671s
    user    0m4.670s
    sys     0m0.000s

So.. which one is faster again?

This "comparison" unfortunately seems too naïve to not be on purpose - no analysis, no real discussion, not even some reasoning about the defaults and why the big difference in numbers. It seems to be just looking for views/comments (even if negative) without any intention to produce real content. What worries me are the ones that will take this for a real benchmark and just "share on facebook" and spread more disinformation.