Omnigraph
Every graph type, one surface.
Add items and pick each one's type from a dropdown -- curves, implicit relations, polar plots, and complex colorings share a single canvas instead of living in separate tabs.
Every graph type on one surface: add items and pick each one's type from its dropdown. The surface upgrades to a 3D scene when any 3D-type item exists (2D items then draw flat on the ground plane); delete the 3D items to return to the 2D canvas. Complex-coloring items render as background layers in list order -- a raster in 2D, a textured ground plane in 3D.
Viewport: x ∈ [-5.00, 5.00], y ∈ [-5.00, 5.00]