Let's remove Quaternions from every 3D Engine

[Nolan]

Let's remove Quaternions from every 3D Engine
http://marctenbosch.com/quaternions/

I haven't had a chance read this really.

What implications does this have for XSI if any?

[blaxxun]

Quaternions are computationally inexpensive. Thats why they are used.
They are hard to grasp because they are 4 dimensional.

https://www.youtube.com/watch?v=zjMuIxRvygQ