Open-source alternatives to Mathematica

I want to pick an open-source replacement for Mathematica. Below is a list from Open Source Everything (CC BY-SA 4.0), in the order its website shows it. The order is a starting point, not a verdict. - GNU Octave: GNU Octave is a free program, shown here through the code for its project website, which explains how the website is built and updated. The material does not describe Octave's calculating features, so its use for math and science is not confirmed here. [Easy setup; devices not listed; replaces partly; GPL-3.0; https://github.com/gnu-octave/gnu-octave.github.io] - Julia: Julia is a programming language built for scientific and technical computing, such as crunching numbers and running simulations. It is aimed at programmers, scientists and engineers who write their own analysis code. [Advanced setup; Windows · Mac · Linux; replaces partly; MIT; https://github.com/JuliaLang/julia] - SageMath: SageMath is free mathematical software meant as an alternative to commercial tools like MATLAB, Mathematica and Maple. It is aimed at students, teachers and researchers who work with math and scientific calculations. [Advanced setup; Windows · Mac · Linux · In your browser; replaces partly; GPL-3.0-or-later; https://github.com/sagemath/sage] Setup rating: "Easy setup" means you can install it like a normal app, use it in a browser. "Advanced setup" means you must run it on your own server or use the command line, or it is a tool for developers. Full details: https://opensourceeverything.org/data/groups/science-math.json Before recommending anything, ask me these three questions (one at a time, in plain words): 1) Which device or devices will I use it on (Windows, Mac, Linux, Android, iPhone)? 2) How comfortable am I with technical setup: only installing apps from a store, happy to follow a step-by-step guide, or comfortable with servers and the command line? 3) What is my budget: free only, or willing to pay for hosting or support? Then recommend one to three projects from this list only, and for each say why, using how fully it replaces the app, its setup rating, and the devices it runs on. If nothing on the list fits me, say so plainly instead of stretching.

Read the list of open-source projects at https://opensourceeverything.org/data/groups/science-math.json. Compare it with my project or idea below. Tell me which projects overlap, what I could reuse instead of rewriting, and what mine does that none of them do. My project or idea: