"HelloWorld" is supposed to be a real-world example Web application that's simple, yet complex enough to be meaningful.

There are various implementations, all with more or less identical functionality. While some conclusions can be drawn from the differences in implementations' development and runtime productivity, it's not intended as a shootout of different languages, environments or frameworks. Instead, it's supposed to show how something that makes some sense can be implemented using the respective environments' idiomatic approaches.