what framework is webfig written in?

I realize this is drifting away from WebFig, but this post by @Larsa and the following post by @pe1chl discusses some of the issues with “rolling your own from scratch” and trying to cram everything into the absolute minimum amount of NAND/flash as is mentioned by @markonen in this post. And then maintaining backward compatibility when things change.

I do concede that WebFig being homegrown is not nearly as problematic as creating your own implementations of standard dynamic routing protocols or defacto standards like openvpn.