I am planning on making a flame fractal engine (no GUI), similar to flam3,
but I need to chose a language. I have one such engine made in Java already, but it is too slow.

What I seek is a compiled language, that can be compiled to both windows and Linux (hence no .NET, GPU language), and preferably with garbage collecting and object-orientation (so no C, and C++).

What languages out there, except D, satisfy these conditions?
Any other thoughts on this?

EDIT: I am more after what similar alternatives there is to D, since D is still in development. 
I will probably choose D, since it has native support for complex numbers, among other things.
However, C++ is more accessible to other developers, but it is a hard language, in my opinion.