How was this stuff compiled? There's no way to reproduce these numbers without compiler flags, at least.

For example, with "rustc fib.rs", I get 10 seconds as a runtime. With "rustc -O fib.rs", to turn on optimizations, I get 0.034s. This makes me pretty sure that they did not turn on optimizations, which means the Rust numbers are very misleading, and possibly, the other languages as well.