You beat me to it! But Sage also has a win version, although online comments suggest it is very slow on windows.
There is a wikipedia list of similar software:
and
https://en.wikipedia.org/wiki/List_of_computer_algebra_systems
https://en.wikipedia.org/wiki/Mathematical_software
https://en.wikipedia.org/wiki/List_of_open-source_software_for_mathematics
Thank you, guys, will look into it!