If you can see this, React is not running. Try running:
npm install -g babel-cli cd examples/basic-jsx-precompile/ npm install babel-preset-react babel example.js --presets react --out-dir=build
This is written with JSX in a separate file and precompiled to vanilla JS by running:
With Babel lower than 6.0
npm install -g babel cd examples/basic-jsx-precompile/ babel example.js --out-dir=build
With Babel 6.0 or higher
npm install -g babel-cli cd examples/basic-jsx-precompile/ npm install babel-preset-react babel example.js --presets react --out-dir=build
Learn more about React at facebook.github.io/react.