Don't want to get into the language shootouts here. But this seems like a horrible way to compare language performance.

There are many more interesting real-life programs tested on computer language shootout website.

In particular, you can't compare C and JVM performance on programs that run for such a short time. The JVM time will be dominated by the time to start up the the JVM and to do the first JIT optimization. I think it is very likely that for a larger fibonnaci number, the JVM performance will come asymptotically close to optimized C's.