This looks like an assembler that writes out byte code that a virtual machine runs (where that VM also supports just-in-time optimization and garbage collection). There seem to be a bunch of these for the Java VM that convert "Java assembly code" into valid .class files (http://tinf2.vub.ac.be/~dvermeir/courses/compilers/javaa/ for example).

An interesting idea -- I work with Java and C# every day, but I never thought of writing assembly code for the JVM or .Net VM.