NuBuildGDX is a fork of BuildGDX aiming for stability, bug fixing and performance improvements.
My goal is to get it in good shape for long term availability and support. I will also be personally maintaining some dependencies for this as some parts are very deeply intertwined with API versions and I don't trust upstream projects to not keep changing API's every release they do.
For renderer's, the PolyGDX will be removed. There is nothing wrong with Polymost, it is tried and tested.
Reduce the bloat, increase the stability.. basically.