If java did the same it would be &quot;java Hello&quot; regardless of whether it was built or not. It would compile <i>and</i> run, or just run if it was already compiled. Not sure why that is a big deal but I do think the separation between jre and sdk in java is mostly a headache. I understand the end user doesn&#x27;t need all the docs etc., but shipping the compiler with the runtime, why not?