How would you like to go to MIT – for free? You can now. Starting this spring, the Massachusetts Institute of Technology will be offering free online courses to anyone, anywhere in the world, through its new digital arm, MITx. These courses will be much more than lectures on videotape. Students will be able to interact with other students online and have access to online labs and self-assessment tools. And here’s the really revolutionary part: If you can show you’ve learned the material, for a small fee, MITx will give you a credential to prove it. No, it’s not a full-blown MIT degree. But employers will probably be impressed.