Attached Link: http://arbaro.sourceforge.net/

I haven't used it with Poser, only with Vue 4, but have a look at Arbaro over at Sourceforge. It's open source, under active development (last version December 17), is written in Java with XML input (so is platform independent and OS X friendly), exports .obj and .dxf as well as POV-ray, and does richly detailed models. There are about a dozen default files included with the download, so you can make your first model in minutes. The models can be very large, but you can adjust the various parameters (number of leaves, number of branches and splits) to decrease the complexity and the file size.