I made a basic pd object that uses juce's plugin hosting routines. To open
a plugin GUI on osx it will need to open a cocoa window. Does anyone know
if that is possible in a pd object? Is pd mac using cocoa yet?

Hi, you can have a look at the CICM Wrapper (CreamLibrary/Dev/c.juce)

https://github.com/CICM/CicmWrapper/tree/master/CreamLibrary/Dev/c.juce

It allows to draw GUIs with the Juce API. If you want to show the juce window, you just have to change the component properties and to disable the tcl/tk part. It's still in development and I can't receive the mouse interactions for the moment, if you find the solution I'll be pleased to know it.

The most "important" part is to call the function "initialiseMac" from the file "ejucebox_startup.mm" and the function "initialiseJuce_GUI" when you initialize your class.

Cheers