When I compile an OSL script in Blender Octane (tried 2018.1.2 and 2018.1.3) it compiles fine but there's no output on the OSL node, which makes it a bit hard to use..
I tried with both my own script and the example from the Blender Octane documentation (both work fine in SA!).
(Also tried both Internal and External)
(Side note: The example in the documentation has an error: The S in shader is in upper case, but should be in lower case)