Retopoflow tools

I was wondering in what programming language were RetopoFlow tools the Polystrip and Contour made? If I remember correctly I think I’ve read some time ago that two developers were behind this add-on, but I don’t recall seeing any information about how long was this tool in development. Does anyone have more insight into this?

All addons for Blender are programmed in Python, and as fr development history, here´s a good read:
https://medium.com/cg-cookie/looking-back-on-retopoflows-development-d7cc41dc7692#.x816tgh5x

Thanks for the link mate, I’ll hold on to that claim about all add-ons being made in Python.