It should be noted that TeXmacs isn't just for authoring documents in the traditional sense. It also allows running shell-like programming sessions, for example

It should be noted that TeXmacs isn't just for authoring documents in the traditional sense. It also allows running shell-like programming sessions, for example a computer algebra system, right inside the document itself. The idea is similar to Mathematica and Jupyter but rather using cells for specific purpose (text, code, ...), in TeXmacs everything is part of the same document.