I decided to port some old code a while back to F#. I then decided to tidy it a little and run it on my Raspberry Pi. I've attempted to make each version as idiomatic to the general language syntax as possible, so there are differences (although the scene rendered at the end is identical)
On my i7 at work it renders the 1280x720 scene in around a second. On my raspberry pi it renders in around 11 minutes

Now going to work on a C++11 version for kicks.
Hope someone out there finds this code useful.