A creative-mode minetest mod that provides tools for constructing mathematical curves/surfaces/solids. It is built with the intention of being used as an educational device in a multivariable / vector calculus course.
First enable the mathplot mod in the world configuration menu.
If not playing as singleplayer, then you will need to grant the "mathplot" privilege.
In-game, search "mathplot" in the inventory screen to find the "MathPlot Origin Node" (white background with picture of xyz-coordinate axes). After placing an Origin node and attempting to dig it, a menu with various options displays; see the "Examples" screen for some pre-defined curves/surfaces/solids!
To destroy an Origin node, dig it using the "MathPlot Origin Node Destroyer" tool. It looks like a set of coordinate axes with a red circle and line through it.