Google's Blockly is similar and available under the Apache License: "Blockly is ...

		rch on May 13, 2014 \| parent \| context \| favorite \| on: MIT's Scratch Team releases Scratch 2.0 editor and... Google's Blockly is similar and available under the Apache License: "Blockly is a component that may be useful for a variety of projects, including educational tools. We want developers to be able to play with Blockly, give feedback, and think of novel uses for it. All the code is free and open source." https://code.google.com/p/blockly/source/browse/trunk/COPYIN...

I've worked on a project that used Blockly and found it to be great : )