The examples are written using ES7 and use decorators. You don't have to use the decorators for React DnD, they are completely optional. The tutorial should give you a good idea about using React DnD in ES5, ES6, or ES7.

Check out the hosted versions of this examples. To run them locally, clone the repo, and run npm install && npm start. It will take a while to start, but after the site is built, you can access the examples by opening http://localhost:8080/ and clicking “Examples” in the navigation bar.