Quote - maybe right a polygon reduction tool for Poser so you export poser charters to my animation app.

what language would you right a polygon reduction app in ?

 

Python

Well, personally I would actually write it in Scala, but Python is easy to learn, has numpy/numeric/whateveritscalledthesedays for doing all the fancy matrix stuff you need for 3d programming, and you can use it from within Poser or, if you prefer, Blender.

That said, polygon reduction is not exactly the first thing I'd try to implement if I was new to both coding and 3d mesh algorithms. I'd suggest you'd start with something simpler for practice: find all the polygons with more than four faces and split them into quads and triangles. When you can do that, Google for "Catmull-Clark" and implement a SubD step. When that works, start to think about polygon reduction.
 

-- I'm not mad at you, just Westphalian.