One of the big new features of Blender 2.65 is the inclusion of the Open Shading Language (OSL) for the Cycles render engine. OSL has been developed by Sony Pictures Imageworks as a shading language for modern path-tracing render engines like Arnold or Cycles. The testbed for OSL, until now, has been a special version of the Arnold render engine used on the films The Amazing Spiderman, Men in Black 3, and Hotel Transylvania.
With Blender 2.65, Cycles has become the first publicly available render engine to support OSL.
View the tutorial
http://cgcookie.com/blender/2012/12/12/introduction-osl-blender-cycles-01/