Codes for the article "Symbolic and Numerical Analysis in General Relativity with Open Source Computer Algebra Systems" by Tolga Birkandan, Ceren Guzelgun, Elif Sirin, Mustafa Can Uslu (arXiv:1703.09738 [gr-qc])
https://arxiv.org/abs/1703.09738
The codes are also available in git branches. The user should switch to the appropriate branch from the "Branch: ..." menu. For example, for the SageMath codes, the "Branch: master" should be changed as "Branch: SageMath" from the dropdown menu.