This is only tangentially related to the post, but one thing I feel sore about is the lack of consolidation of computer algebra efforts. A computer algebra system is one of the most difficult pieces of software to build and make/keep useful, yet it continues to be reinvented decade after decade. (All while Mathematica in the background continues to improve unboundedly.) Seriously, it's easy to pour person-centuries o…
Isn't SageMath based on SymPy?
SageMath is a python frontend to a LARGE number of math backends, not just SymPy.