Redistribute Scratch freely
Put Scratch on a flash drive or burn it to a CD and give it away to your friends, students, and colleagues. Scratch encourages sharing as long as you abide by the license.
You can view the entire Scratch license online at http://info.scratch.mit.edu/Scratch_License. In short, this license grants you the right to distribute Scratch and all its supporting materials, including media files and documentation.
If you do distribute Scratch, you must include the license file and this statement: "Scratch is developed by the Lifelong Kindergarten group at the MIT Media Lab. See http://scratch.mit.edu"
Source code license
Scratch is written in Squeak, an open source implementation of the Smalltalk-80 language. The Scratch source code is available under a second license that grants you the right to modify and distribute the source code as necessary, including derivative works. You can view the license information online at http://info.scratch.mit.edu/Source_Code. Here's a summary...