To others trying to use this demonstration:
Be patient with the page, as it has to download quite a few JAR files in order to be ready to compile and run any test code. To verify that the javapoly is ready to run your code, open the web developer console and wait for it to say &quot;Java Main started&quot;. Additionally, first-time compilation will also need to download additional JARs for the demo code to run. Generally speaking though, the compilation time is a good 5-10 seconds on my computer for the demo code, so be sure to not just spam the compile button like I did :)<p><pre><code>  ----
</code></pre>
Just a friendly note to the author of this page:
The total download size of this page&#x27;s underlying Java resources are much larger than I realized (maybe a collective 30-40MB). Given that I waited almost 5 minutes after clicking &quot;Compile &amp; Run!&quot; for nothing to happen (because I had clicked it well before the runtime JARs had fully downloaded), I would suggest to at least add a progress bar or something to let users know when they can actually compile and run the demo code, in addition to some acknowledgement that the code is compiling. This is definitely an interesting project though.