Gregory's Server
In my ongoing quest for simple React setups, this article is mind blowingly good:
https://kentcdodds.com/blog/super-simple-start-to-react
It explains how to set up a react app with just HTML and JS files, no webpack or browserify or anything. It is fully a toy implementation BUT it helped me understand a lot of the "magic" underlying React in a way that I never had before. It even shows how to write JSX embedded in the HTML file (by including Babel in a script tag).
@darius I absolutely shipped non-public-facing code this way when React was first taking off, in order to build a thing that would have been super painful to do in jQuery. The docs used to do a really good job of explaining this as a first-class option! I loved how it could be gently introduced into an existing codebase without having to rewrite everything.
Then everybody went and rewrote everything using it.