Except for the fact that JNI is such a piece of utter... garbage ... as far as performance is concerned. One has to think twice, thrice ...countless times before jumping back and forth over the runtime bridge of JVM and native. Not that Python is that good at it either, but better than JNI, almost everything is. The best I have seen is Lua&#x27;s FFI.<p>I consider it an accident of history that Numpy, Scipy, Pandas, Scikits got written for Python and not Lua. Thanks to Luajit I think Lua would have been a better choice. Now that cause has been taken up by Torch and Julia.<p>JVM by itself is terrible for reaching close to the FLOPS that the CPU is capable of. Try sparse matrix multiply with it and see it for yourself.