This is an environment to program your Arduino board based on a dataflow editor. This is based on the blocks.js project.
See the online live example here.
Simply clone this repository and clone blocks.js:
git clone https://github.com/Gregwar/blocks.js
Then open index.html.
This is under the CC-BY-NC license: https://creativecommons.org/licenses/by-nc/2.0/