Thomas Dinges shows off early version of the development of the Open Source Shader Language Node in Blender. The open shader language will allow you to build, connect and use your own shaders using the OSL that was developed by Sony Pictures Imageworks for use in its in-house renderer used for feature film animation and visual effects. The OSL is a language for programmable shading in advanced renderers and other applications, ideal for describing materials, lights, displacement, and pattern generation.
Every shader node in Blender is implemented in both backends, so you can switch back and forth here without worrying about your material setup
Here Thomas shows off the development of the new OSL Script Node in the Cycles Render Engine inside Blender, and while OSL isnt included in any official Blender builds to date, the updated OSL code is in the trunk with the exception of the OSL Script Node. Thomas notes that the OSL feature won’t be added into the upcoming Blender 2.64 release, but will most likely make it to 2.65.