I was researching routing table algorithms a while back, and this algorithm came up in several places, but I never saw an open source implementation of it anywhere. Maybe because it was patented back in the 90s. As far as I can see, the patents it had is now voided, due to not paying the fees for them.

This implementation is slightly modified as compared to how it was originally published. It now works with the much bigger BGP routing table today. It also does away with the maptable, saving a memory reference.

I'm sure the part where it is building the two trees could be improved, but I think this will do for now.