Add.osl — This is an osl version of the Add Texture node, discussed here.

Clip.osl — This is a shader clip osl, where the texture color (input a) is clipped by the values specified in the clip 1 and clip 2 values.

Complex_IOR.osl — This osl shader has N and K values for each color channel (R, G, B). It is replaced by the RGB IOR mode on Metallic materials, discussed here.

InstanceID.osl — This osl shader will output one of two texture inputs, as determined by the Instance ID value assigned within the shader. The result can also be swapped by enabling the "Swap" option.

Layer-with-Alpha.osl — This osl shader will layer up to four textures together, using alpha channels if present, and offers four simple blending operations: mix; multiply; add; and subtract. The Composite material offers more options, and is discussed here.

Layer.osl — This osl shader will layer up to four textures together and offers four simple blending operations: mix; multiply; add; and subtract. The Composite material offers more options, and is discussed here.

mm_ImageTexture.osl — This is an osl version of the Image Texture node, written by MilanM. It has an option to disable filtering, which can prove useful in certain circumstances.

Multiplier.osl — This osl shader will multiply a texture input (a) by a value speficied by the Mult. slider. A slider value of 0 will be black; a value of 1 will match the input texture perfectly. Values above 1 will increase the brightness of the input texture.

ObjectColor.osl — This shader will use the Display color of the object as the diffuse color value of a given material. Requires the Use Display Color toggle enabled in Octane Object Tag > Object layer tab, discussed here. 

Raytype.osl — This shader is essentially the same as the Ray Switch node, discussed here. 

Texture-Repeat.osl; Texture-Tiler1.osl; Tiling1.osl — These three osl shaders use cellular noise to tile texture inputs, controlled by the input sliders.