I am, strictly speaking, not a practitioner of Test-driven Design, or TDD. I know what it is, and I know that people like to argue about what they think it is and what they think it is not.
Just show the essence of the idea. I think we can all agree on that, can't we? For this video I approached a number of friends and asked them about what they considered the essence of TDD to be, and how they think of using it. By the way – each of them hedged their opinions with a variation of "this isn't strictly TDD… but…".
TDD requires discipline and you're not alone if you sort of do it. As long as you're testing your code!
You can find the code for each of the demos up on GitHub.