I did a project like this to get three body physics for an iOS/Android app Three Body. (http://nbodyphysics.com/blog/2015/12/ http://nbodyphysics.com/blog/2015/

I did a project like this to get three body physics for an iOS/Android app Three Body. (http://nbodyphysics.com/blog/2015/12/ http://nbodyphysics.com/blog/2015/12/). Converting Fortran from 1973 into C# for Unity. This code (only 1000 or so lines) is very dense. I also cleaned up my own mess from 1996, when I recently re-released a General Relativity package for Maple, GRTensorIII (https://github.com/grtensor/grtensor https://github.com/grtensor/grtensor) that was part of my PhD work. The 1996 code is not that tragic, but is far from my best work - although I did earn my PhD.