Converting geometry for WebGL

I’m building a web form to accommodate users uploading .obj and .fbx 3D models to a site. We need a server-side solution to convert these files to Collada (dae).

It would be massively helpful if someone could point me in the right direction as I have no solid ideas on a possible solution as yet. I’d like to hear what others think before I go down one path in-particular.

Firstthoughts are something along the lines of a server-side python/perl script triggered off by the PHP during upload?

Many thanks in advance,