I remember checking this project out around 2014 and it seemed it was all being done in Sketchup using ruby. Now it looks like it's mainly being done in Grasshopper/Rhino (visual scripting) with some components being done using custom C# or Python scripts. I think its the right move, as Grasshopper/Rhino is a more powerful CAD engine, and has a more useful and extensive ecosystem of plugins for them to develop around.
