Take a look at SageManifolds: https://hyperspace.uni-frankfurt.de/2017/01/20/sagemanifolds/ https://hyperspace.uni-frankfurt.de/2017/01/20/sagemanifolds... My

Take a look at SageManifolds: https://hyperspace.uni-frankfurt.de/2017/01/20/sagemanifolds/ https://hyperspace.uni-frankfurt.de/2017/01/20/sagemanifolds... My understanding is the numerical GR community is moving in this direction. The theory people tend to roll their own inside of Mathematica or Maple. Some Maple users use GRTensorIII (https://github.com/grtensor/grtensor https://github.com/grtensor/grtensor) Disclaimer: I am a co-creator of GRTensorIII