Hmmm... when I click on the Horses link, I see its 3 notebooks, with a blue clone & run button. When clicked, I get prompted to sign in (requires any msft account like outlook, xbox, hotmail, ...). Once you sign in (or create an account), you'll end up in Docker/Jupyter instance with the 3 notebooks. Clicking on the first one and doing a Run All, should give you:

http://imgur.com/a/JgcqP

What happens when you click the Intro to F# sample on the front page? It should render the notebook and if you clone, it should prompt to sign in as above. Hope this helps.