[doug1001]

Mr Stein released the first version of SageMath some time ago--not sure how long but maybe 2007.

among other things, SageMath reconciled the confusing namespace soup that is scientific python (numpy, scipy, and matplotlib--three brilliant libraries with partial overlap in functionality and in package names) which SageMath gathered (along with other libraries like SymPy) and put them under a single rubric, 'SageMath'--one (large) install and you have all of scientific python.

SageMath also included a notebook

seems not such a big deal now with Anaconda and Jupyter notebook, but in 2007 it certainly was.