Source: Thimble by Mozilla – An online code editor for learners & educators.

Thimble gets a nice update.  Here is the quickest webpage I could make: Kicking the Thimble.

You can now upload files, css, image, javascript ect and create & edit multiple files. Code completion seems a lot better to me too. It grumbles about Safari s oI switched to chrome which is recommended along with FireFox.

Obviously useful for learning to create webpages.