There are open source alternatives. The one I'm somewhat involved in is Maxima which is one of the oldest open source projects that is still being developed.
And yes, I think it is lacking a better UI (wxMaxima works but needs more polish I think) and particularly more appealing documentation. Your video is very interesting!
And yes, I think it is lacking a better UI (wxMaxima works but needs more polish I think) and particularly more appealing documentation. Your video is very interesting!