Well, on the plus side, all the modern JVMs do just-in-time recompilation, and have a had fair amount of optimization work done on them. On the minus side, JVM

Well, on the plus side, all the modern JVMs do just-in-time recompilation, and have a had fair amount of optimization work done on them. On the minus side, JVMs take a long time to start up and don't really interface very well with native code (JNI sucks). The JVM also tends to be pretty poor at using memory effectively. All objects need to contain class and lock pointers, for example. On a 64-bit machine, this generally means that the minimum size of an object is around 16 bytes (may vary by JVM). Will Java still be used decades from now? Of course. I mean people are still using FORTRAN, COBOL, and Lisp, some of the first compiled languages ever to be developed in the 1950s and 1960. (Yes, Lisp is that old-- and FORTRAN came first.) How popular will it still be in X years? Who knows. Consult a fortune teller-- sorry, "analyst."