Gridpaper is a figure editor that runs entirely in your browser. Under the hood, it's gnuplot 6 compiled to WebAssembly, which means you get all that rendering power without installing anything. No account, no server, your data never leaves your machine.
The core idea is that there are no chart types. Instead you compose layers from a small set of building blocks: 12 geometric marks (curves, bars, heatmaps, vectors, surfaces…) across 5 coordinate systems. A scatter plot with a fit line isn't a special widget — it's two layers. A grouped bar chart is three bar layers in a group set to dodge. It sounds abstract, but in practice it means you can build a lot from very few pieces.
Some things worth poking at:
* The example gallery has 50 figures you can click to open in the editor
* Try importing a CSV (drag it onto the canvas)
* Switch to polar or 3D coordinates and watch the available marks change
* The design page¹ explains the compositional grammar if that sort of thing interests you
I should be upfront: it's not open source yet. I'm a solo developer and I want to get the core solid first. The plan is to open the rendering engine (the gnuplot WASM bridge and compiler) first, then the full editor.
Happy to answer questions about any of it!
¹ gridpaper.org/design