Chad P. wrote:
-snip-
I’m also not sure the jruby implementation’s numbers here are
representative of JRuby’s strengths. Does JRuby benefit from the
benefits of Java’s optimizing VM for long-running processes?
I know it’s probably suffering, in micro-benchmarks, from increased
start-up times as it loads the VM.
JRuby is suffering from being 1.0
“JRuby 1.0 was focused almost entirely on one goal: Ruby 1.8.x
compatibility. … The next step is making it run as well as possible.
… The heavy lifting for performance and scalability are coming up
…”
Please notice that JRuby is running some of those “micro-benchmarks”
for 2 1/2 hours before dwelling too much on JVM startup-time 
http://shootout.alioth.debian.org/gp4sandbox/benchmark.php?test=all&lang=jruby&lang2=jruby
I’m surprised to see python’s median so low. Are these benchmarks
heavy on bytecode-optimized Python, or do they tend to use standard
interpreted Python?
A build and run log is shown for each program:
http://shootout.alioth.debian.org/gp4sandbox/benchmark.php?test=meteor&lang=python&id=2#log
And then there’s Psyco
http://shootout.alioth.debian.org/gp4sandbox/benchmark.php?test=all&lang=psyco&lang2=python