Following a osl in cycles tutorial http://cgcookie.com/blender/cgc-courses/introduction-to-osl-in-blender-cycles/ And the option of what shading system to use is missing and also I cannot activate the scripting node when I am in node editing mode. I am using blender 2.67b, And I have tried to use the search option (as shown in attached image). If any body knows what is/or what i am doing wrong could they please inform me. Cheers