You can also use a computer algebra system (CAS) to perform computations and get the output in mathml, for example the free CAS maxima.

wxMaxima is something like jupyter notebook but developed with wxWindows by a solo developer. ?? is help for command

I just copy pasted:

(%i2) ?? mathml; -- Function: mathml_display (<form>) Produces MathML output. (%i1) load("alt-display.mac")$ (%i2) set_alt_display(2,mathml_display); <math xmlns="http://www.w3.org/1998/Math/MathML"> <mi>mlabel</mi> <mfenced separators=""><msub><mi>%o</mi> <mn>2</mn></msub> <mo>,</mo><mi>done</mi> </mfenced> </math> (%o2) true