Obj-C cross platform compilation

[Salter, Adam Q]

Dear all,

I am investigating writing a cross platform application (game)... I really like the Obj-C syntax and object model. My question is this: what do I need to do this?

- can I use GNUStep?
- do I really need to subclass NSObject (makes life a lot simpler I imagine with custom allocation/deallocation) for my own objects?

- would the binary run slower than straight C++?
- does it require an extra library/run-time environment? (if so this is a definite negative)

SDL/OpenGL are easily cross platform and with those and a nice View/Controller/Data model I should be cooking quite quickly - if it is really possible.

I guess I'm really asking more about Obj-C than GNUStep, but maybe not. I'm no expert.

Any suggestions/help/source code appreciated,

Thanks,
Adam