Every version of Java since JDK 1.2 has had JIT compilation. However, none of the Sun JVM environments will store the compiled version of a .class file in a .jar or in a (Windows) .exe or (Unix) coff.
The JIT got significantly better in JDK 1.3. I am pretty sure that there were improvements made again in 1.4 but I don't know precisely.
If you really want to save the .exe, you can try The GNU Java Compiler
. It's pretty neat stuff. You can mix Java and C++ (without having to do JNI, but you have to use the GNU linker). It can compile .java or .class files. A disadvantage however is that it does not yet fully support Toolkit (which means no Swing).
I do not see where JBuilder has anything more than the standard HotSpot JIT compiler that comes with Sun JDK 1.4. I could be wrong, but I think that when the ads talk about using JIT compiler for fast execution, they just mean that the code is compiled with HotSpot (which is Sun's JIT, and which does not operate outside of memory).