Idea for teaching:
If each student sets up a free GitHub account —
They can make Gists, like this:
Could these be used for peer grading? Easy to share.
Once the student has a GitHub account, he/she can write code in Codepen (http://codepen.io/) and automatically save to Gist from there.
I saw this map (second image on page) at The New York Times, and it made me want to learn more abut D3.