There is a very powerful plug-in interface, but its never been sufficiently documented to allow anyone other than the original author write plug-ins for it. This is one of the first things I talked to Nik about when handing it over after the 32bit port, now he has gotten to know the program via all the bug fixing, he is better placed to be able to document the plug-in API. I hope to see a plug-in SDK similar to the one CC produced for Artworks, and we all know what happened when a talented programmer got his hands on that!