PAMPI is a free software to create presentations easily.

presentations are written in text files, - so they can be modified easily - the files syntax (Markdown) is easily learnt - many examples of usable Markdown are available at https://enacit1.epfl.ch/markdown-pandoc They are converted to web pages (HTML files) - one can view them with a browser - one can publish them online, grab them on a USB stick, etc. In PAMPI's interface, the Markdown file is displaied in the left side and on can view the result in the right side.

Every step of a presentation can be located in any position in a 3D space - one provides its coordinates - one can specify its zoom factor - one can specify rotations Maths can be authored with KaTeX.

Here are many examples: https://en.wikibooks.org/wiki/LaTeX/Mathematics.