The Wolfram Language and Mathematica on Raspberry Pi, for free article tells that The Raspberry Pi Foundation has announced a partnership with Wolfram Research to bundle a free copy of Mathematica and the Wolfram Language into future Raspbian images. Future Raspbian images will ship with the Wolfram Language and Mathematica by default; existing users can install them today. Raspberry Pi is only the second computer ever on which Mathematica has been bundled for free use.
Stephen Wolfram has a long posting on the topic titled Putting the Wolfram Language (and Mathematica) on Every Raspberry Pi. It tells that they are also releasing alongside the Raspberry Pi bundle a Remote Development Kit, that allows one to develop code and maintain a notebook interface on a standard computer, while seamlessly executing code on a networked remote Raspberry Pi. Raspberry Pi is just the first pilot for the Wolfram Language. The aim is that with those new tools the aim is to create a new path for learning programming—and connecting it to the real world—that a great many people are going to be able to benefit from.