I should probably comment on this paper from my colleague Robert Hundt , where he writes the same benchmark in Java, Scala, Go, Python and C++ ( TL;DR here ). Short version: Initially, C++ was faster than Scala, and Scala was faster than Java. I volunteered to make some improvements, which ended up with the C++ and Java implementations being about the same speed. Some C++ hackers then went and improved the C++ benchmark by another ~6x, and I didn't think I should go down that road. Imagine my surprise when I got this email from a friend of mine this morning: Date: Fri, 3 Jun 2011 03:20:48 -0700 Subject: Java Tunings To: Jeremy "Note that Jeremy deliberately refused to optimize the code further, many of the C++ optimizations would apply to the Java version as well." Slacker. Gee, thanks for making me look good, Robert. (Actually, I had approved that language, but I didn't realize anyone would actually read the paper. :) ) Anyway, I was not just being obdurate here;...
Jeremy Manson's blog, which goes into great detail either about concurrency in Java, or anything else that the author happens to feel is interesting or relevant to the target audience.