I always wanted to write a proper physically-based path tracer. So during summer 2015 I started writing myrtille (sorry for the bad pun) only using C++11, the STL and OpenMP. I stopped after getting a diffuse path tracer to render fast enough. I still plan to come back at some point and add a better handling of materials and change my vector class to hopefully allow automatic vectorization to work.
You can find the source code here
Here are some progress pics (hover for some description):

woodworking nerd edition

Here is a box I made in 2013 for a friend. As he is a geek himself I thought it would be interesting to make the box mostly by coding.
The model was generated using Python in Maya (and this was way more painful than it should be). The top follows as sine surface and the pixels have a random elevation from it.
The machining was done on birch wood at the Institute of Making with (big) help from Rich.