Which plugin the Nvidia? Looks like it is windows I did not see a mac version but have to make sure you get the either the 32bit or 64bit  for your version of Photoshop here is where you can get the lastest version https://developer.nvidia.com/gameworksdownload#?dn=texture-tools-for-adobe-photoshop-8-55 If your asking about the ones for Gimp that I am unsure about all I know is that when installing Gimp you have to do custom install at least on Windows and make sure that included Python package is installed so the scripts will work no sure how it installs on a Mac. Hope this helps some Bobby

Lobo3433

Blender Maya & 3D Forum Moderator 

Renderosity Store

My Free Stuff

Facebook

Twitter

Renderosity Blender 3D Facebook Page