Group: Rooting unrooted trees

Assuming the following is true:

In the absence of a good outgroup the root may be positioned by assuming approximately equal evolutionary rates over all the branches. In this way the root is put at the midpoint of the longest pathway between two OTUs. This way of rooting is called mid-point rooting.

I am trying to implement a way of rooting an unrooted tree using ruby. Having been to BOSC2007 in Vienna I have found that tree objects have been implemented in bioruby to some extent. I will try to adapt my code to be able to added to the bioruby code base.