I think projects like this are great examples to learn from, especially when executed to a high standard.

Somewhere between partial examples of a bit of a project, and a full blown 'proper' application that would be too big to use as an example, there is a sweet spot for project like this. I think that's why they occasionally bubble up. Certainly if there was such a thing as a single 'best' sample project for any language I was interested in, I'd like to have a look at it.